DECISION DEADLINE: Rep. Todd Akin insists he's staying in the Senate race. But Missouri election law allows candidates to withdraw 11 weeks before Election Day — meaning Akin has until 5 p.m. Tuesday to formally withdraw. Otherwise, a court order would be needed to remove him from the ballot.

IF AKIN DROPS OUT: State Republicans would have two weeks to name a replacement.

WHO'S ON DECK? If Akin gets out, attention turns to his primary competitors: John Brunner and Sarah Steelman. But among other possibles are Missouri Auditor Tom Schweich and two members of Missouri's House delegation, Blaine Luetkemeyer and Jo Ann Emerson.