The big-spending conservative super PAC Crossroads GPS is pulling advertising money from the Missouri Senate race following Rep. Todd Akin's "legitimate rape" comments, Crossroads spokesman Nate Hodson told Yahoo News. As Politico first reported, the group began canceling its ad buys in support of Akin this morning.

The move follows Texas Sen. John Cornyn, who's in charge of the Senate Republican campaign arm, suggesting Akin carefully consider his campaign before continuing forward. "Congressman Akin's statements were wrong, offensive, and indefensible," Cornyn said in a statement. "I recognize that this is a difficult time for him, but over the next twenty-four hours, Congressman Akin should carefully consider what is best for him, his family, the Republican Party, and the values that he cares about and has fought for throughout his career in public service." Mitt Romney echoed the rhetoric in an interview in New Hampshire, saying Akin should think about his candidacy over the next 24 hours.

In an interview with Mike Huckabee Monday, Akin apologized for his comments but said he would not drop out. "I'm not a quitter," Akin said.

--Chris Moody contributed to this report.