Tea Party test in Nebraska as conservative groups push Sasse for Senate

Tea Party Republicans looking to get their groove back are eyeing Tuesday's Republican Senate primary race in Nebraska, where leading conservative groups and figures are closing ranks behind a university president's candidacy.

The election is closely watched, as the Tea Party movement and its allies have struggled to execute the kind of electoral coups that ousted GOP incumbents tagged as too moderate in 2010 and 2012. Last week in North Carolina, the Tea Party-aligned candidate lost to state House Speaker Thom Tillis in the Senate GOP primary there.

But Nebraska Senate candidate Ben Sasse, president of Midland University, appears to have a lead in the polls as he enters Tuesday's contest for the open seat left by retiring Republican Sen. Mike Johanns. He's facing off against former state treasurer Shane Osborn, as well as Sid Dinsdale, an Omaha businessman who recently loaned his campaign $1 million and may be picking up steam in the race.

Sasse is campaigning as an anti-regulation, anti-ObamaCare, pro-gun rights "outsider."

"I think we need to elect more people who want to make Washington less important," he recently told the Fremont Tribune.

Sasse enjoys support from the Club for Growth, Tea Party Patriots and other major conservative organizations, as well as former Alaska Gov. Sarah Palin, Texas GOP Sen. Ted Cruz, and Utah GOP Sen. Mike Lee, who have recently joined him on the campaign trail.

But Osborn has fought back against Sasse's more-conservative-than-thou message, running a new ad accusing his rival of supporting the 2010 federal health care law.

Sasse has made his opposition to the Affordable Care Act the centerpiece of his campaign. His photo on the cover of the conservative National Review in January was featured above the headline: "Obamacare's Nebraska Nemesis."

However, Sasse advised former Health and Human Services Secretary Mike Leavitt's firm as the group reached out to businesses and organizations in 2010 to explain and implement the new law.

Osborn recently began running a 30-second TV ad linking Sasse to writings and speeches from several years earlier commenting on elements that would become part of the law firmly opposed by most Republicans. The ad begins with a video clip of Osborn speaking in 2009, predicting federal health care legislation would raise costs.

Osborn also aired ads pointing to Sasse, who has the backing of anti-establishment Senate Conservative Fund, having lived in Washington, D.C., during and after his time with the Bush administration.

Sasse's team has claimed its innocence from the closing-weeks negative advertising, although his campaign last month released documents showing that Osborn had lived and voted in Florida while he was in the Navy.

"We've never run a negative ad. We have run a 100-percent positive campaign" on television and radio, Sasse spokesman Tyler Grassmeyer said.

Instead, several outside super PACs that support Sasse have aired ads accusing Osborn of overspending as treasurer and one ripping him for circulating an unauthorized memo praising his actions piloting a U.S. spy plane forced down by China in 2001.

A poll conducted last week showed Sasse opening up a sizeable 14-point lead in the race. The Magellan Strategies poll showed Sasse with 38 percent, Dinsdale with 24 percent and Osborn with 20 percent. The poll had a margin of error of 4.28 percentage points.

A separate poll in April by NSON Opinion Strategy, though, showed Sasse leading Osborn by just 2 points. In that poll, Dinsdale was trailing far behind those two candidates.

On the Democratic side, trial attorney and Keystone pipeline foe Dave Domina is running against Air Force veteran Larry Marvin for the nomination.

The Associated Press contributed to this report.