In Nebraska, another GOP establishment candidate in peril

This April 15, 2012, photo, shows state Treasurer Don Stenberg, right, during a debate against state Attorney General Jon Bruning, center, and state Sen. Deb Fischer, left, in Omaha, Neb. The three top Republicans vying for Nebraskaâ??s U.S. Senate nomination scrambled through a final full day of campaigning on Monday, May 14, 2012, as the race appeared to tighten and election officials predicted above-average turnout for the nationally watched contest.
AP Photo/Nati Harnik
Nebraska, Bruning, Fischer, Stenberg
This April 15, 2012, photo, shows state Treasurer Don Stenberg, right, during a debate against state Attorney General Jon Bruning, center, and state Sen. Deb Fischer, left, in Omaha, Neb. The three top Republicans vying for NebraskaâÂÂs U.S. Senate nomination scrambled through a final full day of campaigning on Monday, May 14, 2012, as the race appeared to tighten and election officials predicted above-average turnout for the nationally watched contest.
AP Photo/Nati Harnik

(CBS News) Third party groups have been heavily backing a conservative candidate in Nebraska's Republican Senate primary -- and they may manage to take down the establishment pick today. However, their candidate could lose, too.

For some time, the GOP Senate primary looked like a fight between Nebraska Attorney General Jon Bruning, the establishment favorite, and State Treasurer Don Stenberg. In recent days, however, a third candidate -- State Sen. Deb Fischer -- has gained traction.

It appears as if the expensive mud-slinging between Bruning and Stenberg could have helped Fischer. And in the final days of the primary campaign, Fischer has secured her own wealthy backer, as well as the support of big names like Sarah Palin.

Heading into today's primary, the results look impossible to predict. A poll conducted Sunday -- commissioned by Joe Ricketts, a wealthy businessman backing Fischer -- shows Bruning leading with 38 percent and Fischer close behind with 35 percent. Stenberg takes 16 percent in the poll, and 8 percent remain undecided.

The poll results should be taken with a grain of salt since its backer has a vested interest in the results. Moreover, the results of a low-turnout race like a Senate primary can be hard to predict.

But for what it's worth, the poll shows that 31 percent of likely Republican voters have unfavorable views of both Bruning and Stenberg -- suggesting their fight has taken a toll. Just 10 percent have an unfavorable view of Fischer, while she remains unknown to 25 percent of primary voters.

Fischer's relatively low profile isn't surprising, given the level of spending in the race on behalf of her opponents.

Outside groups have spent more than $2.3 million in the Nebraska Senate primary cycle -- more than in any other state except Indiana, where a Tea Party-backed candidate ousted a longtime incumbent in the primary.

Most of the outside spending has come from South Carolina Sen. Jim DeMint's Senate Conservatives Fund and from the anti-tax group Club for Growth. Both of those groups are backing Stenberg, though the Club for Growth has put their emphasis on attacking Bruning.

Both the Bruning and Stenberg campaigns raised most of their first quarter funds from outside of Nebraska, while 90 percent of Fischer's first quarter fundraising came from in-state, the Omaha World-Herald reports.

Bruning remains the presumed frontrunner, with the largest campaign war chest and an endorsement from the World-Herald.

The dynamics of the race began to change, however, when two polls last week showed Fischer gaining traction. Then on Saturday, Ricketts, the owner of the Chicago Cubs and founder of TD Ameritrade, poured $200,000 into the race on Fischer's behalf. He paid for an ad questioning Bruning's character, as well as an ad praising Fischer.

Fischer also recently picked up endorsements from Nebraska Rep. Jeff Fortenberry and former Alaska Gov. Sarah Palin.

On Monday evening, Palin posted a Facebook note with a note that she and her husband Todd Palin wrote to Fischer. "Winning over voters through personal interactions is the way to go. People are tired of outside interests spending millions of dollars in political attack ads. We're glad to see your grassroots efforts paying off!" the letter said. Todd Palin also recorded a robocall for Fischer.

The Palins aren't the only nationally-recognized names to get involved in the race this week. Former Arkansas Gov. Mike Huckabee and former Sen. Rick Santorum both threw their weight behind Bruning, the Hill notes. Huckabee recorded a robocall for Bruning, calling him "a proven conservative who has led the Constitutional challenge to Obamacare."