Tuesday was the final day in which Akin could withdraw from the race without a court order. As the 5 p.m. deadline to withdraw neared, Republican leaders intensified their pressure on Akin to exit.
Sen. Roy Blunt issued a joint statement Tuesday with all four of Missouri's living former Republican senators — John Ashcroft, Kit Bond, Jim Talent and John Danforth — saying "it serves the national interest" for Akin to step aside.
Pointing to the group, Romney said the congressman should "accept their counsel."
A Romney aide said the candidate had been inclined to let Akin make the decision on his own. But after the Missouri lawmakers called for Akin to go, Romney wanted to make his position clear, said the aide, who requested anonymity because the aide was not authorized to publicly discuss Romney's thinking.
Akin provoked the political uproar when he was asked in the KTVI interview whether his general opposition to abortion extends to women who have been raped.
"It seems to me, first of all, from what I understand from doctors, that's really rare. If it's a legitimate rape, the female body has ways to try to shut that whole thing down," Akin said.
It's not clear if Akin's campaign will have the financial support to wage a prolonged advertising battle against McCaskill in the expensive St. Louis and Kansas City markets and the Republican-rich area of southwest Missouri.
The campaign arm of the Senate Republicans has already withdrawn $5 million in advertising planned for the Missouri race. The Karl Rove-backed Crossroads organization pulled its ads too. A fundraiser planned in Washington for next month was called off after all of the dozen GOP senators who had agreed to participate pulled out.
Crossroads President and CEO Steven Law suggested Tuesday that Akin was potentially helping Democrats retain their Senate majority by remaining in the race.
"The stakes in this election are far bigger than any one individual," said Brian Walsh, a spokesman for the National Republican Senatorial Campaign Committee. By staying in the race, Akin "is putting at great risk many of the issues that he and others in the Republican Party are fighting for."
Without that financial backing, Akin will need the support of social conservatives, who have formed his political base through a 12-year congressional career.
Noreen McCann, who lives in the same suburban St. Louis area as Akin, said Tuesday that his rape comment hasn't weakened her support for him. McCann expressed frustration that Akin was being publicly flayed for his ill-chosen words while other Democrats — specifically President Bill Clinton — have survived scandals that included accusations of sexual impropriety and lies.
Akin "is a man of principle. I trust and respect his integrity and his commitment to defending American values," said McCann, who had passed out Akin fliers on primary election day. "I think he wants to defend all innocent human life. If he misspoke, or it was in the wrong context, that is not a major problem for me."
But other Missouri Republicans are second-guessing their support for Akin.
Steven and Carolyn Sipes, a pair of retired public school teachers who are GOP committee members in southwest Missouri's Christian County, both voted for Akin in the primary. Carolyn is now doing some soul-searching prayer about whether Akin remains the best choice. Her husband believes Republicans would have a better shot of unseating McCaskill without Akin.
"If he decides to stay in, I'll back him to the hilt," Steven Sipes said. But "I think it would be better probably if he did drop out at this point. He's getting a lot of negative publicity."
Akin's campaign released an open letter Tuesday from Jack Willke, former president of the U.S. National Right to Life Committee, stating he was "outraged at how quickly Republican leaders have deserted" Akin.