By Dan Merica and Gregory Krieg, CNN/StyleMagazine.com Newswire

A string of damaging legal developments rattled Republicans on Tuesday and further heightened the stakes of the 2018 midterm elections less than three months away.

The startling, coast-to-coast rat-a-tat-tat -- a conviction in Virginia, a confession in New York and new charges in California -- left the GOP off balance and had Democrats, already eyeing a sharper anti-corruption message for the fall, arguing voters should put them in power in Congress to serve as a check on President Donald Trump.

If Democrats take over the House in November -- and with it, the committee chairmanships and the subpoena power that comes with the gavels -- Trump would suddenly be open to a whole new, harsher brand of scrutiny, with investigations sure to dog the administration straight through to the 2020 election.

Tuesday's news also put front and center a thornier issue for Democrats ahead of November and one Republicans believe could energize Trump's base: impeachment.

Party leaders and parts of the liberal base have often found themselves at odds over the prospect of seeking to remove the President, with House Minority Leader Nancy Pelosi, who has frequently sought to tamp down such talk, telling the Associated Press on Wednesday that impeachment is still "not on the table."

Democratic campaign aides in states won by Trump in 2016 reached by CNN said they had no plans to alter their strategies -- and that the party should be wary of reacting too quickly to fast-moving developments.

"There's a lag time for the average person, the person who is somewhat politically aware but is more worried about paying bills or health care premiums," one aide to a campaign in a red state told CNN. "Maybe there will be new data and the polling says, 'Wow, the worm has finally turned, he's done it, it's finally happened, he's gone too far, how dare he?' -- but I think we're still a little away from having any actionable data (that says that)."

Although a number of Democrats already have seized on impeachment -- namely mega-donor Tom Steyer, who has led a public campaign calling for Trump's ouster, and California Rep. Maxine Waters, who has drawn Trump's ire for doing the same -- most Democrats have avoided taking the issue on head on, and Pelosi has said repeatedly that impeachment is not a priority for the party.

One senior Republican official working on the midterms, even while charting how to overcome the growing corruption cloud, said the hope inside the party was Democrats would overplay their hand and the conversation would most overtly "shift toward impeachment."

"Take the bait Democrats," the official pleaded.

The more likely tactic is an increasingly sharp focus on the alleged corruption and ethics scandals that have surrounded the Trump administration for more than a year.

Tuesday's damaging double-dose of legal news for the President, with his former personal attorney and fixer Michael Cohen pleading guilty to eight criminal counts and implicating Trump in his court statement, made the political case clearer. Shortly before Cohen's confession in New York, Paul Manafort, the man who led Trump's presidential campaign for five months, was found guilty of eight financial crimes in Alexandria, Virginia.

The hits didn't stop there.

Moments later, news broke that California GOP Rep. Duncan Hunter and his wife were indicted on charges related to the misuse of $250,000 worth of campaign funds for personal expenses and the filing of false campaign finance records. Hunter is the second Republican House member to be indicted this month after New York Rep. Chris Collins, who was charged with securities fraud, wire fraud and false statements stemming from an alleged insider trading scheme. Hunter and Collins were the first two House members to endorse Trump's presidential bid in 2016.

Taken together, the news played right into the anti-corruption messaging already being deployed by Democrats in the run-up to the 2018 midterms.

"Today's guilty verdicts against Trump campaign Chairman Paul Manafort & guilty plea by Trump's personal lawyer, Michael Cohen, are further evidence of the rampant #CultureOfCorruption & criminality at the heart of Trump's inner circle," Pelosi, D-California, tweeted on Tuesday.

It wouldn't be a totally novel approach for the party as it seeks to reclaim power in a midterm year.

Democrats used the same term -- "culture of corruption" -- in 2006 when they won 31 seats in the House and five in the Senate to take control by hammering Republicans over a mess of scandals surrounding California Rep. Duke Cunningham, who confessed to accepting bribes; the fallout from the lobbying scandal engulfing Jack Abramoff; and the resignation of Florida Rep. Mark Foley in September of that year after he was caught sending sexually explicit messages to House pages.

In a sign of messaging to come, Aftab Pureval, a Democrat hoping to flip Ohio's first congressional district in November, slammed Republican Rep. Steve Chabot for being part of the problem and then turned the indictment on Trump.

"We need to actually drain the swamp," he said. "We have to hold people accountable and I'm glad the courts did that today. But the best way we can do that is to elect new leaders in November."

Longtime Democrats see evidence that a similar strategy could work again this fall.

"People were already uneasy about continuing Trump's Congress of yes men," said Jesse Ferguson, a longtime Democratic operative, "but now they're going to demand checks and balances to end the cover-ups."

The revelations could steepen what is already expected to be an uphill climb for Republicans, especially with independent voters, and further threaten the majorities they've used to effectively shield the White House from more aggressive oversight.

But their messaging strategy, like the President's, has remained constant: dismiss Cohen as a liar; cast Manafort's conviction as unrelated to the Russia probe; and stress -- over and again -- that there was "no collusion" between Trump and Moscow ahead of the 2016 election.

Meanwhile, Democratic candidates and operatives said that while Tuesday's events sharpened that corruption line of attack, the fundamentals remained that the 2018 fight will likely remain focused on issues like tax policy and health care.

"Every day, the dark cloud hanging over the Republican Party grows more ominous," said Democratic Congressional Campaign Committees spokeswoman Meredith Kelly. "House Republicans must answer for the Trump Administration's scandals -- and often their own ethical issues, while Democrats continue to focus on lowering the cost of healthcare, increasing wages and bringing upstanding, ethical leadership to Washington."