WASHINGTON -- Tuesday's Nebraska Republican Senate primary has divided the conservative movement, essentially pitting Rick Santorum against Sarah Palin against Sen. Rand Paul (R-Ky.).
Three frontrunners have emerged in the bid for the party's nomination to take on Democrat Bob Kerrey in November, who previously served in both the Senate and as the state's governor. Nebraska has an open U.S. Senate seat since Democrat Ben Nelson is retiring, and Republicans see it as a prime opportunity to aid their quest to retake the Senate.
But so far, the Republican candidates have been busier attacking each other than Kerrey.
Attorney General Jon Bruning (R), state Sen. Deb Fischer (R-NE 43rd District) and state Treasurer Don Stenberg (R) have all picked up endorsements from conservative heavyweights.
Santorum recently endorsed Bruning, while Palin threw her support behind Fischer, praising her "conservative principles." Stenberg is backed by Paul and the Club for Growth.
Bruning has consistently led in the polls and was seen as the likely nominee. While he appears to be ahead, the Omaha World-Herald predicts a "wild finish" Tuesday.
Joe Ricketts, who owns the Chicago Cubs with his family and started TD Ameritrade, also threw in $200,000 in a last-minute attempt to doom Bruning, placing one spot that criticizes Bruning and another that praises Fischer. The Bruning campaign called the ad buy "illegal."
Stenberg has benefited the most from third-party spending, according to the World-Herald. The Club for Growth, Sen. Jim DeMint's (R-S.C.) Senate Conservatives Fund, and FreedomWorks for America have spent $2.1 million on his behalf. Bruning, however, has raised the most money of all the candidates and spent $1.3 million on media buys. Stenberg's campaign spent just $195,000 on media, and Fischer, about $150,000.
Conservative commentator Matt Lewis characterized the endorsements of prominent national conservatives in the race as "schizophrenic," saying it was "hard to blame the voters for being unclear about which candidate is the real conservative."
The choice was clearer, for example, in the last high-profile Senate race, where Richard Mourdock beat incumbent Sen. Richard Lugar (R-Ind.) for the party's nomination. Mourdock had the backing of conservative groups like the Club for Growth, while Lugar was perceived to be more moderate.
Stenberg is trying to create that dynamic in the Nebraska race.
"I'd be the Richard Mourdock of the Nebraska race -- the person who has the support of Club for Growth, U.S. Sen. Jim DeMint, FreedomWorks," he told NPR. "Jon Bruning is the establishment candidate. He has the establishment money and establishment endorsements."
Bruning, who helped lead the challenge to President Barack Obama's health-care reform law in the Supreme Court, disputed that characterization, saying he is "not looking for compromise" on issues of balancing the budget and reducing the national debt.
University of Nebraska political science professor Michael Wagner also said there was not much difference between the candidates policy-wise.
"There's not a whole lot of space between them in terms of how they would behave as a U.S. senator to the best that we can tell," Wagner said. "Bruning is a little more ambitious and seems to be a little more willing to play the bipartisan game in a way that Stenberg doesn't seem as willing to play."
Fischer has attracted national attention in recent weeks, with staffers at the National Republican Senatorial Committee reportedly arguing internally that "she would be a strong challenger to Mr. Kerrey in a presidential election year in which Republican turnout is likely to be strong in this deeply conservative state."
At times, the race has veered into the bizarre and personal. Bruning accused Stenberg of being "creepy" for requesting to follow his 14-year-old daughter on Twitter. And Bruning also attracted national attention for comparing welfare recipients to raccoons.
CORRECTION: This article originally stated that Santorum endorsed Stenberg. He endorsed Bruning.