Former House Speaker Newt Gingrich, once a rival of Perry and Santorum for the GOP presidential nomination, spent Monday campaigning with Akin in the candidate's St. Louis County congressional district, which he has represented for six terms. Gingrich attended a press conference and fundraiser luncheon with Akin. Rick Tyler, a former Gingrich aide who led the pro-Gingrich super PAC Winning Our Future, began working as Akin's spokesman Aug. 30.
On Tuesday, minutes after Akin's withdrawal deadline had passed, the Missouri Republican Party issued a statement of support. "Just like all of our GOP candidates elected in the August primary, the Missouri Republican Party stands behind Congressman Todd Akin in his race for United State Senate," state party chairman David Cole said. The state party had not called on Akin to withdraw but had distanced itself from the candidate, according to Akin's campaign.
DeMint's PAC, the Senate Conservatives Fund, endorsed Akin Thursday morning after its supporters pledged $290,000 to help him. The group Freedom's Defense Fund reportedly will spend $250,000 on TV, radio, and Internet ads to boost Akin.
Other groups are standing by their decision not to involve themselves in Missouri.
"We have absolutely no plans to get involved in this race," Club for Growth spokesman Barney Keller told ABC News. FreedomWorks did not respond to an email inquiry.
"You kind of know where we are on Missouri," American Crossroads spokesman Nate Hodson said. "We don't discuss any strategy moving forward."
Arlette Saenz contributed to this report.