Akin's comments, that pregnancy in cases of "legitimate rape" is rare because "the female body has ways to shut that whole thing down," drew fire from Republicans nationwide, with most quickly making public statements to distance themselves from Akin.

McCaskill's new ad, which comes as Akin seems to be gaining steam in recent polling and as he and his allies launch a significant volley of ads in the final days, uses clips of those statements from some of the most prominent Republicans to come out against the candidate at the time.

"Is Todd Akin fit to serve in the Senate? Mitt Romney doesn't think so," a voiceover says at the opening.

The ad goes on to play a clip of Romney disavowing Akin soon after his comments came to light.

"What he said was indefensible, was wrong, it was offensive, and he should step out of the race," Romney says.

It also cites a statement made by Missouri Sen. Roy BluntRoy Dean BluntThe Hill's Whip List: Republicans try again on ObamaCare repeal Another health funding cliff puts care for millions at risk Top Senate Dem: We're going forward with understanding we can work with White House on DACA MORE and former Sens. John Danforth and Kit Bond at the time, calling for Akin to step out of the race, and comments Sen. John McCainJohn Sidney McCainRubio asks Army to kick out West Point grad with pro-communist posts The VA's woes cannot be pinned on any singular administration Overnight Defense: Mattis offers support for Iran deal | McCain blocks nominees over Afghanistan strategy | Trump, Tillerson spilt raises new questions about N. Korea policy MORE (R-Ariz.) made, that Akin "would not be welcome by Republicans" in the Senate.

But Blunt and Bond have since backed Akin, and in recent days, Akin has received a flood of support from outside Republican groups attempting to boost him to a win.

Akin adviser Rick Tyler accused McCaskill of trying to distract from her record with the new ad.

"Notice that McCaskill's ads are never about her record. That's because her record includes voting for Obamacare, tax increases, debt increases, Wall Street bailouts, and a Stimulus Bill where $20 million of taxpayer money went to her family business. That's not a record she can run on so any distraction will do," he said in an email to The Hill.

McCaskill's new ad is an attempt to refresh Akin's comments in voters' minds as they go to the polls.

Watch the ad: