By Alex Rogers, CNN

(CNN) -- Former Gov. John Hickenlooper attacked Sen. Cory Gardner in a new ad released Wednesday, charging that the Colorado Republican is "ready to rush through a Supreme Court justice at lightning speed" rather than address a host of other issues.

The ad is one of the first in the country to invoke the fight over Justice Ruth Bader Ginsburg's successor, underscoring how Democrats view the vacancy as a political winner in blue states, where the party base is furious at Republicans for moving forward to confirm a nominee and shift the Court even further to the right.

"Cory Gardner has taken no action to lower health care costs, lower prescription drug prices, rebuild our infrastructure, fight climate change or provide economic relief in this pandemic for five months," says Hickenlooper in the ad. "But boy oh boy, Cory is ready to rush through a Supreme Court justice at lightning speed."

"The next court will decide whether to rip up protections for people with pre-existing conditions, whether women still have a right to choose, and really what justice means in this country," he adds.

Gardner is one of the most vulnerable Republican senators in the country, running in a state that went for Hillary Clinton over Donald Trump by five points in the 2016 presidential race. His campaign did not immediately respond to CNN requests for comment. It's a Tilt Democratic race, according to Inside Elections with Nathan L. Gonzales.

In March 2016, Gardner, like almost every other Republican senator, supported blocking then-President Barack Obama's nominee, Judge Merrick Garland, from filling the seat left by the late conservative Justice Antonin Scalia. "Our next election is too soon and the stakes are too high; the American people deserve a role in this process as the next Supreme Court Justice will influence the direction of this country for years to come," he said at the time.

After Ginsburg's death on Friday, the Colorado senator quickly backed the Senate Republican strategy to consider Trump's to-be-announced nominee to replace her even though Election Day is less than six weeks away.

"I have and will continue to support judicial nominees who will protect our Constitution, not legislate from the bench, and uphold the law," said Gardner in a statement earlier this week. "Should a qualified nominee who meets this criteria be put forward, I will vote to confirm."

It's unclear exactly how the vacancy will affect the fight for control of the Senate. Democrats are confident that it will help them in blue states like Colorado and Maine, where Republican Sen. Susan Collins faces a tough reelection race, while Republicans are confident it will help them in red states like Montana. If Sen. Doug Jones loses in deep red Alabama, Democrats needs to win four seats and the White House to take control of the chamber.

Democratic Senate candidates including Hickenlooper have advocated for fulfilling Ginsburg's "most fervent wish" to not be replaced until after the next presidential inauguration, when a President Joe Biden could choose her replacement. Democrats have no power to block a nearly unified Senate Republican majority, but are warning voters that a Supreme Court with six conservative justices could dismantle the Affordable Care Act and its protections for those with pre-existing conditions. The Court hears a crucial case on the law's constitutionality a week after Election Day.

Gardner has defended himself from attacks over his support to repeal the ACA, saying in an ad that he'll protect people with pre-existing conditions like his mother, "no matter what happens to Obamacare."

His campaign also aired a new ad on Wednesday, referencing an infamous ad Hickenlooper ran in 2010, in which the Democrat took a shower with his clothes on because he couldn't stand all the negative ads.

"Now, it's Hickenlooper who's running nasty ads," says Gardner in his ad, as he leaves a shower wearing a blue shirt and tie. "You and I may not always agree, but I stay true and work hard for Colorado.