The head of the super PAC supporting Sen. Rand Paul's presidential bid is facing federal charges for an alleged scheme to buy the support of a Iowa state senator during Paul's father's 2012 presidential run. To secure support for Ron Paul, then a Texas congressman who was running as a libertarian candidate and ultimately came in third in the state caucus, Jesse Benton and two other operatives allegedly bribed and paid then-state Sen. Kent Sorenson with $70,000 to switch his support from then-Rep. Michele Bachmann, R-Minn., to the elder Paul.

The money was paid to Sorenson, according to the indictment, through what were labeled as legitimate campaign expenditures, and then funneled through two companies before landing in the hands of Sorenson and his wife. The payments came in monthly installments of $8,000. After hearing of the indictment, the Paul campaign called foul, pointing out that the timing of the Justice Department filing is just one day before the first Republican debate, which the Kentucky senator is in.

"Sen. Rand Paul is disappointed that the Obama Justice Department chose to release this just prior to the highly anticipated first Republican presidential debate," a statement from the campaign said. "It certainly appears suspiciously timed and possibly, politically motivated. Additionally, these actions are from 2012 and have nothing to do with our campaign." A statement from a Benton attorney made the same claim.

RTX1N5SG Republican presidential candidates (top row from left) Donald Trump, Jeb Bush, Scott Walker, Mike Huckabee, Ben Carson, (bottow row from left) Ted Cruz, Marco Rubio, Rand Paul, Chris Christie and John Kasich are seen in a combo of recent file photos. Photo: Reuters

Benton has reportedly said he will seek "expedient review" so that the charges can be completed within two months. Benton told Rep. Mike Harmon, who is from Paul's home state of Kentucky and also has Benton working for him, that Paul is standing by him and so are several of his other clients, Harmon told Politico.

The allegations come nearly a year after Sorenson pleaded guilty to charges of obstruction of justice and causing a political campaign to falsely report expenditures. They also come at a hard time in Paul's presidential run. Paul, who has stood out for his unorthodox stands on foreign policy and civil liberties, has lagged in fundraising. While he has lagged in polls, too, he was able to make the prime-time debate stage Thursday night. That stage was limited to the top 10 candidates in polls.

Benton runs America's Liberty PAC, the only super PAC sanctioned by the Paul campaign. Super PACs are political action committees that can accept unlimited amounts of contributions to spend on political campaigns. They must disclose their donors and they must maintain a certain amount of distance from the actual candidate committees. They cannot make campaign plans alongside the candidates.