Akin spent six terms in Congress and was backed by the missouri GOP for the Senate. He's as "Establishment" as it gets. And, the Tea Party Express has already called on him to withdraw.
You can paint this as a fight against the "GOP Leadership" all you want, but he brought this on himself, and only his stubborn hubris (and Huckabee's money) are keeping him from doing the honorable thing.
The ABR’s found a new avenue to hand over 4 more years to Obama, don’t kid yourself about these people.