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The former top Iowa adviser to Michele Bachmann's failed presidential campaign pleaded guilty to concealing payments he received from former U.S. Rep. Ron Paul's presidential campaign to switch his support and ditch Bachmann.

Former Iowa state Sen. Kent Sorenson entered the guilty plea for one count of causing a federal campaign committee to falsely report its expenditures and one count of obstruction of justice.

Sorenson admitted he had supported one campaign for the 2012 presidential election, but from October to December 2011, "he met and secretly negotiated with a second political campaign to switch his support to that second campaign in exchange for concealed payments that amounted to $73,000," according to a Justice Department release.

The Justice Department said Sorenson was paid about $8,000 a month with payments funneled through two companies before reaching Sorenson and his wife.

Sorenson publicly announced that he switched his support from Bachmann to Paul on Dec. 28, 2011, just days before the Iowa Caucus. The defection was a significant blow to Bachmann, whose campaign lost steam after she won the Iowa straw poll in August of that year.

At the time, Sorenson said it was clear that Bachmann was no longer a viable contender.

"The fact is, there is a clear top tier in the race for the Republican nomination for president, both here in Iowa and nationally," Sorenson said. "Ron Paul is easily the most conservative of this group."

Bachmann's congressional staff did not immediately respond to a request for comment on Sorenson's plea.

In his plea, Sorenson also admitted that he gave false testimony to an independent counsel appointed at the request of the Iowa Senate Ethics Committee.

"Today, Mr. Sorenson has taken responsibility for his crimes," said Acting Assistant Director in Charge Timothy A. Gallagher. "Exploiting the political process for personal gain will not be tolerated, and we will continue to pursue those who commit such illegal actions."

Last year, a special investigator found probable cause that Sorenson violated Iowa's ethic rules by taking money from committees tied to Bachmann's campaign by laundering the money through separate consulting firms.

Iowa Senate ethics rules prohibit legislators from receiving payment for work on political campaigns.

On two separate occasions, Sorenson issued written statements to the Senate Ethics Committee, denying that the Bachmann campaign paid him.

Bachmann has also denied the allegations that her campaign paid Sorenson.