Omaha, Nebraska (Reuters) - A female rancher is banking on a humorous "political bull" ad and a high-profile endorsement to win the Republican primary for a U.S. Senate seat in Nebraska, where the party sees a chance to cut into the Democratic majority in November's election.
State Senator Deb Fischer has used a late endorsement from former vice presidential candidate Sarah Palin and the ad featuring two Angus bulls named after the men she is running against to enliven the race for the Republican nomination to fill the seat of retiring Democratic Senator Ben Nelson.
The winner of the Republican race will faces presumptive Democratic nominee Bob Kerrey, a high-profile former senator and governor of the state, in November. Kerrey's candidacy has boosted Democratic hopes of retaining the seat in a state that has drifted to the right in recent years.
Until recently, the Republican nomination appeared likely to go to state Attorney General Jon Bruning, who raised the most money and was leading in the polls over Fischer and state Treasurer Don Stenberg.
But Fischer, a rancher in Nebraska's remote Sandhills region, has benefited from the ads financed by former Omaha businessman Jo Ricketts, whose family owns the Chicago Cubs baseball team, which attacked Bruning on ethical questions.
A poll taken on May 13 by We Ask America showed Fischer surging into the lead at 39 percent to 34 percent for Bruning. The automated poll of 1,109 likely Republican voters had a margin of error of 3 percent.
Critics have hit out at Bruning for investing in private businesses since he began serving as Nebraska attorney general in 2002.
In his campaign, Bruning has highlighted that he was one of several state attorneys general who filed a lawsuit against President Barack Obama's healthcare law, which is now before the U.S. Supreme Court.
Stenberg is making his fourth try for the U.S. Senate. He has cast himself as the true conservative in the race with the backing of many leaders of the Tea Party movement, including U.S. senators Jim DeMint of South Carolina and Rand Paul of Kentucky.
Bruning has led in fundraising with $3.5 million. Stenberg has raised $700,000 and Fischer $400,000, according to the latest campaign finance reports.
Democrats now hold a 53 to 47 edge in the Senate, which allows them to control the agenda and committee majorities.
Nebraska has drifted conservative in recent years and Nelson announced his retirement when it looked like he would have a tough race for re-election.
(Editing by Greg McCune and David Brunnstrom)