Todd Akin is a Missouri congressman and Senate candidate. And obviously a fuckwit of epic proportion.
I'm not sure what he meant, or even whether he knows what he meant. Bafflingly, wondrously stupid.
More on the story here.
UPDATE: The silver lining is that he's gone from being favourite to take that Senate seat to, er, not favourite.
UPDATE ii: The Guardian has a fascinating piece on the (literally) medieval thinking behind Akin's statement.