Originally Published: 06 SEP 22 05:05 ET

Updated: 06 SEP 22 09:05 ET

By Eric Bradner, Gregory Krieg, Dan Merica, Michael Warren and Jeff Zeleny, CNN

(CNN) -- The two-month sprint to the midterm elections is set to take place on political terrain that is much less settled than Republicans had hoped it would be, with improving economic news, a raging battle over abortion rights and former President Donald Trump's return to the forefront raising Democrats' hopes that the party can hold onto its narrow majority in the House or Senate.

Republicans entered the year riding strong historical trends, with President Joe Biden's approval rating slipping as the first midterm elections of his presidency approached, and poised to benefit from an electorate eager to assign blame for soaring inflation.

But gas prices have dropped, and Biden's approval rating has ticked upward. Republicans, meanwhile, have watched as their electorate followed Trump's endorsements in a handful of key races for Senate seats and governorships. Those Trump-endorsed candidates -- many of whom had built their campaigns around his lies about widespread election fraud -- have struggled to broaden their appeal to moderates and independents who will decide November's key races.

The FBI search of Mar-a-Lago has shifted the spotlight from Biden, whom Republicans want to run against, to Trump, who remains a galvanizing force for Democrats and suburban moderates who oppose him.

The most significant factor could be the Supreme Court's decision to end federal abortion rights. Since the late June decision, Democrats have scored a string of surprising victories.

In deep-red Kansas, voters resoundingly rejected an effort to end the state's constitutional protection of abortion rights. In a special election for a bellwether House seat in New York, in which abortion was a key issue, the Democratic candidate won. And in last week in Alaska, little-known Democratic former state lawmaker Mary Peltola defeated Republican former Gov. Sarah Palin in a ranked-choice special election for a House seat that had been in GOP hands for nearly half a century.

Republicans are expressing anxiety -- not about any shift in the landscape so far but about the unknown issues that could crop up in the final weeks before Election Day and disrupt the perceptions of swing voters.

"It's like you're up in the beginning of the fourth quarter and you want to limit the variables," said Matt Gorman, a Republican strategist. "You've just got to run out the clock."

While Republicans attempt to keep the focus on Biden, Democrats argue that, with the passage of their health care and climate bill, the party has more to sell to voters as a result of Biden's first two years in office.

The day after the Inflation Reduction Act became law, House Democratic Caucus Chair Hakeem Jeffries, after ticking off nearly every notable piece of legislation signed by Biden -- from the American Rescue Plan, to the bipartisan infrastructure, gun and manufacturing bills -- heaped praise on Biden.

"If someone were to say that a president had a record of accomplishment that I just described, without putting a timeframe on it, the logical response would be that person had a successful two-term presidency," the New York Democrat said.

GOP concerns about candidate quality build

After Labor Day -- long seen as the unofficial start to campaign season -- candidates typically shift into a higher gear. Debates are scheduled, rallies are more frequent, get-out-the-vote efforts are launched and the television advertising battles escalate.

The fall campaign is opening with an air of uncertainty, with the President leading the charge in trying to turn the midterm election into a stark contrast with Republicans -- rather than simply a referendum on Democratic control of Washington.

"We have a choice," Biden said Monday evening, speaking at a rally outside Pittsburgh. "Trump and the MAGA Republicans made their choice. We can choose to build a better America, or we can continue down this sliding path to oblivion, to where we don't want to go."

The President's visits to Wisconsin and Pennsylvania on Labor Day were the latest sign that those two states -- and their respective Senate seats, both held by Republicans -- are the biggest prizes Democrats are eyeing over the next two months. The comments from Biden come after months of surveys and focus groups, with a tailored-message to try and open the door to winning over independent and even some Republican voters frustrated with Trump's return.

"We found ourselves in a situation where we were either going to look forward or look backwards and it's clear which way he wants to look," Biden said, referring to his predecessor. "It's clear which way the new MAGA Republicans are -- they're extreme and democracy's really at stake."

Trump also visited Pennsylvania for a rally over the weekend, where he railed against the FBI search of his Mar-a-Lago home, but barely touted the Senate and gubernatorial candidates he was there to support.

Pennsylvania is perhaps the best window into Republicans' struggles in recent months. The GOP is attempting to hold onto the seat of retiring Sen. Pat Toomey, and nominated Trump-endorsed celebrity doctor Mehmet Oz to take on Democrat John Fetterman, the current lieutenant governor.

Republicans had also hoped to win the governor's office, with term-limited Democratic Gov. Tom Wolf not running. But the party's voters nominated another Trump-backed candidate, far-right state lawmaker Doug Mastriano, a leading proponent of the former President's election fraud lies. The GOP is now pumping millions of dollars into Oz's race, and has all but abandoned Mastriano.

Concerns about the quality of candidates Republicans have nominated are growing not just in Pennsylvania, but across the political map. In Arizona, the GOP nominated a slate of Trump-endorsed election deniers with competitive Senate and governor's races on the ballot. In Georgia, former football star Herschel Walker has faced a series of damaging revelations about his personal history in his race against Democratic Sen. Raphael Warnock, who's running for a full six-year term after winning a 2021 special election.

The clearest case of a candidate struggling in a race Republicans need to win is Oz in Pennsylvania, who, after spending millions of his own money to win the commonwealth's primary in May, stopped that personal spending over the summer and largely disappeared from the campaign trail while Fetterman recovered from a stroke. Top Republicans now believe Oz squandered the summer, allowing a Democratic candidate who wasn't even campaigning to open a polling lead.

But Oz is not alone. Republicans have privately and publicly expressed concerns about Walker in Georgia, Blake Masters in Arizona and Adam Laxalt in Nevada. In New Hampshire, a state that holds its primary next week, Republicans are also growing increasingly concerned that Don Bolduc, a retired United States Army brigadier general, could defeat New Hampshire Senate President Chuck Morse in the Republican Senate primary -- a win that some believe would make Democratic Sen. Maggie Hassan's path to reelection easier.

All of it has led Senate Minority Leader Mitch McConnell to temper expectations that his party will control the Senate in January.

"I think there's probably a greater likelihood the House flips than the Senate," McConnell said in August. "Senate races are just different. They're statewide. ... Candidate quality has a lot to do with the outcome."

That led to a feud between McConnell and Florida Sen. Rick Scott, the chairman of the National Republican Senatorial Committee, the party's Senate campaign arm, to burst into public view last week.

Politico published an interview with Scott saying that he and McConnell have a "strategic disagreement" over the party's candidates, and the Washington Examiner published an op-ed by Scott taking issue with the view that those candidates could cost the GOP the Senate.

"Ultimately, though, when you complain and lament that we have 'bad candidates,' what you are really saying is that you have contempt for the voters who chose them. Now we are at the heart of the matter," Scott wrote. "Much of Washington's chattering class disrespects and secretly (or not so secretly) loathes Republican voters."

Increase in women registering to vote after abortion ruling

Though energy seems to have been on Democrats' side in the wake of the Supreme Court ending federal abortion rights protections, the ruling's most significant impact could be the ways in which it reshapes the electorate.

Ahead of the Kansas constitutional referendum, voter registration among women surged -- one reason proponents believe voters opted to keep the abortion protections.

With just weeks before the midterms, though, it appears a similar trend is at play in a range of key states, according to Tom Bonier, the head of TargetSmart, a Democratic political data tracking firm. Catalist, another political data firm, found a similar trend -- and while the numbers of new registrations were relatively small, there are noticeable trends toward Democrats and women.

Bonier put it bluntly: In his decades of analyzing voter registration data, he has never seen the kind of surge among women that has followed the Supreme Court's decision, leading him to believe that the 2022 midterms may not be as big a Republican wave as history may suggest.

"If women turn out at a rate, maybe 10 points higher than men, you see a dramatically different electorate than you would have expected to see in the midterm election that dynamically should favor Republicans given everything else," said Bonier, who added that even small shifts in women voters could mean dramatic shifts in midterm races. "I truly have never seen anything like that in election data."

Bonier and analysts have argued this is the reason that several top Republican candidates are scrubbing their websites of strict abortion positions and de-prioritizing abortion as an issue at events.

Last month, Democrat Pat Ryan won a special election in New York's 19th Congressional District largely by centering his campaign on abortion rights, describing the election as a referendum on Roe. Weeks earlier, Kansans -- in a high turnout vote that cut across traditional partisan lines -- rejected a ballot measure that would've allowed its legislature to pursue a ban.

But Ryan's run posed different challenge. Voters in the upstate district were choosing between candidates, not voting directly on an issue -- even as Ryan insisted they were inextricable. In the end, though, his message appeared to win the day and further embolden Democrats.

Abortion rights are "something people feel viscerally and more deeply than any single policy issue. And when you hit that nerve, you get the response you got here last night that, that you got in Kansas a few weeks ago," he told CNN the morning after his victory. "And I think we will continue to see that happen, especially because far right members of Congress and other far right folks out there are doubling down on the extremism, calling for a national abortion ban, wanting to put doctors in jail. It's just so divorced from where, where the vast, vast, vast majority of Americans are."

In a Sunday interview on Fox News, Rep. Tom Emmer, chairman of the National Republican Congressional Committee, the GOP's House campaign arm, argued that Democratic efforts to rally voters around abortion rights would backfire.

But in the process, he handed his opponents another inflammatory sound bite -- calling House legislation to codify the protections from Roe v. Wade "the Chinese genocide bill."

"If Democrats want to make abortion the main issue, when every poll we've seen says that the economy and the cost of living is the number one issue, good luck to them trying to defend their extreme position. Every one of them voted for what I call the Chinese genocide bill, which would allow abortion up to moments before a child takes its first breath. I think our candidates know how to message that and they'll be just fine in the midterms."

Governor's races test GOP's candidate quality

Governor's seats in all five states that flipped from Trump to Biden in 2020 are on the ballot this year, lending those races importance that stretches well beyond their borders.

In Michigan and Wisconsin, Democratic Govs. Gretchen Whitmer and Tony Evers, respectively, are vying for second terms, while Pennsylvania state Attorney General Josh Shapiro is running to keep the seat in Democratic hands with Wolf on the way out.

"We've had numerous Republicans take off that red jersey, cross the line and endorse my candidacy," Shapiro told CNN on Monday, arguing that he is capitalizing on a rival he views as extreme. "We're going to keep building a big broad coalition and we're going to win in November."

Trump endorsed the eventual Republican nominees in all three races and, were they to win, each could potentially preside over GOP governing trifectas. Republicans already control state government in Arizona, where Republican nominee Kari Lake, a Trump-allied former TV news anchor, made election denial the centerpiece of her primary campaign. Georgia Gov. Brian Kemp, a rare Republican to break with Trump's election lies but keep his grip on power, is locked in a rematch of his 2018 race with Democrat Stacey Abrams.

In all these contests, and others from Nevada to Maine, Democrats are hammering their GOP rivals over right-wing extremism in the party. They are betting that the message will be especially effecitve in Pennsylvania, where Mastriano, who was in Washington on January 6, 2021, has said he wants to ban abortion, with no exceptions.

"This is an issue about Republicans talking about taking away rights and freedoms and what that means for other right freedoms," Democratic Governors Association spokesman David Turner said. "There's a real, visceral sentiment amongst voters about what Republicans are doing that's driving a lot of the conversation."

Republicans, though, are making a different calculation -- and arguing that statewide races like those for governor are going to turn on a combination of more provincial concerns and the overall state of the economy, which remains voters' top concern in most polling.

"Voters are more concerned with the kitchen table issues that are affecting their everyday lives, more so than an issue that certainly invigorates the base Democratic voters," Republican Governors Association spokesman Jesse Hunt said.

He pinpointed Nevada, where Democratic Gov. Steve Sisolak is faced with both a slow-recovering economy and a tough challenge from Republican Joe Lombardo, the Clark County sheriff, as a prime pick-up opportunity for the GOP.

Still, optimism among many Republican officials over the state of governors' races has dimmed over the past few months, as GOP primary voters mostly followed Trump's lead -- sometimes with a nudge from meddling Democrats -- and picked nominees widely viewed as less acceptable to the broader electorate.

The picture for Republicans in states like Texas and Florida, where Trump comfortably won in 2016 and 2020, is brighter.

Florida Gov. Ron DeSantis, who could use reelection as a springboard for a potential 2024 presidential run, has emerged as a prolific fundraiser and, after Trump, the second most popular figure among Republicans nationwide.

Democratic nominee Charlie Crist is trying not only to unseat DeSantis, but to turn the tide for a party that hasn't won a race for governor in Florida since 1994. Crist held the job more recently, from 2007 to 2011, but was elected as a Republican before leaving the party to become an independent and then eventually joining the Democrats. He lost a 2014 challenge as the Democratic nominee to then-Gov. Rick Scott, now the state's junior GOP senator.

Texas Gov. Greg Abbott is less closely tied to Trump, but won his endorsement and re-nomination in a landslide. Democrat Beto O'Rourke, the former congressman from El Paso, is trying to recreate the grassroots fervor that nearly carried him to victory over Sen. Ted Cruz four years ago, but will not have a blue wave at his back this time around.