A well-known state senator who just days before Iowa's caucus in the 2012 presidential campaign abruptly flipped his support from Rep. Michele Bachmann to then-Rep. Ron Paul of Texas allegedly sought payments from Paul in return for his endorsement, according to materials published Wednesday.

State Sen. Kent Sorenson, a Republican, wanted $8,000 per month through the fall of 2012 and a donation of $100,000 to his leadership political action committee, according to an Oct. 29, 2011, email written by one of his associates to John Tate, Paul's campaign manager. The email was published by OpenSecrets.org of the nonpartisan Center for Responsive Politics and the conservative TheIowaRepublican.com.

A few weeks later, a deputy campaign manager for Paul handed a check for $30,000 to Sorenson's wife, according to Dennis Fusaro, a onetime Paul aide who went public with the allegations this week.

At the time of Sorenson's defection, Bachmann alleged that he was being paid to endorse Paul, a charge the Texas congressman and his campaign vigorously denied.