Washington – A former top official for Michele Bachmann's failed presidential campaign pleaded guilty on Wednesday to concealing payments he received from the presidential campaign of former Rep. Ron Paul, R-Texas, to switch his support and ditch Bachmann.

Former Iowa state Sen. Kent Sorenson, Bachmann's one-time campaign adviser in Iowa, 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 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."

After his announcement, Bachmann claimed Sorenson admitted to her that he took payments from Paul to defect. Bachmann did not immediately respond to a request for comment on Sorenson's plea.

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

"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."

Sorenson has been granted immunity from further prosecution on federal and state charges as part of the plea deal.

Bachmann investigations continue

It remains unclear what implications Sorenson's plea could have for Bachmann, whose presidential campaign remains under investigation by several federal agencies.

In December FBI field agents seized materials from Sorenson's home related to his work for the Paul and Bachmann campaigns.

The raid came two months after a special investigator appointed by the Iowa Supreme Court found probable cause that Sorenson violated its 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.

The congresswoman's presidential campaign also faces an active investigation by the U.S. House Ethics Committee.

A federal grand jury probe of top Bachmann campaign operatives, including Bachmann's husband, Marcus Bachmann, was revealed last fall.

The U.S. Justice Department has subpoenaed financial registers of the National Fiscal Conservative (NFC) Political Action Committee, which allegedly agreed to help raise funds for a Bachmann campaign mailer ahead of the Iowa caucuses.

The Federal Election Commission is also probing allegations of illegal coordination between the Bachmann campaign and the NFC PAC, as well as with Bachmann's own political action committee, MichelePAC.

Bachmann announced last spring that she would not seek another term in Congress.

Corey Mitchell is a correspondent in the Star Tribune Washington Bureau • Twitter: @C_C_Mitchell