SALT LAKE CITY -- The conservative Club for Growth has spent $120,000 trying to oust GOP U.S. Sen. Bob Bennett of Utah from office.
Bennett is seeking a fourth term this fall but has come under criticism for his support of a bailout of the nation's financial industry.
Bennett faces seven challengers from within his own party, although the Club for Growth hasn't endorsed any of them.
Republicans will choose their nominee at the state convention in May. Much of the Club for Growth's spending was directed at getting Republicans opposed to Bennett elected as delegates to the convention.
"We spent nearly half of our spending on things we hoped would drive up caucus turnout," said the club's executive director, David Keating. "Our theory was that new caucus-goers would not be friendly to Bennett."
To win the nomination at the convention, Bennett would have to get 60 percent of the 3,500 delegate votes. If after several rounds of voting no candidate gets 60 percent, the top two vote-getters would be forced into a June primary.
Bennett's opponents are hoping to knock him out at the convention, where campaigning is less expensive than in a primary.
Federal records show the Club for Growth's expenditures include nearly $46,000 for phone banks and other activities to get people to the caucuses, nearly $26,000 for TV ads, another $26,000 for Internet ads and Web site costs and $22,000 for mailings.
"This spending included a very heavy Fox News cable buy, and heavy Facebook and Internet advertising. As a result of the Internet ads, over 8,000 people signed up on our (StopBobBennett.com) Web site or our Facebook fan page to help us increase turnout at the caucuses," Keating said.
Bennett said the spending has helped some of his challengers, but caused a backlash among some voters.
"Some of my challengers who would have had difficulty coming after me because of lack of support are more buoyant than they would be otherwise because they can piggyback on the Club for Growth," he said.
Bennett said many people who have told him they've opposed him have repeated Club for Growth material.
But, "If I can meet with delegates personally, I find that it is easy for me to answer and rebut them and have those concerns go away."