U.S. Sen. Deb Fischer notched an easy Republican primary victory on Tuesday despite challenges from four GOP candidates who sought to take her seat in deep-red Nebraska.

Fischer will face Democrat Jane Raybould, a Lincoln City Councilwoman who defeated three primary opponents. Fischer enters the general election as a heavy favorite to win a second term.

Fischer has focused on her first-term accomplishments, including her work to pass highway funding legislation. She also stressed her Senate experience, such as her position on an Armed Services subcommittee.

The others seeking the GOP nomination were retired Omaha math professor Jack Heidel; writer and retired air conditioning technician Dennis Frank Macek; former finance manager Jeffrey Lynn Stein; and Lincoln businessman Todd Watson.

Some of Fischer's primary opponents argued she hasn't been conservative enough, but Fischer received endorsements from a majority of the state's elected Republican officials as well as major farm and business groups. Before being elected to the Senate, she was a rancher and state legislator.

Raybould was the best-known candidate in the Democratic field, partly because of her unsuccessful bid for lieutenant governor in 2014 with running mate Chuck Hassebrook. Raybould has served on the City Council since 2015 and helps run her family's grocery store chain.

The other Democratic hopefuls were retired farmer, attorney and judge Frank Svoboda of Lincoln; retired Fremont real estate broker Larry Marvin; and Chris Janicek, the owner of an Omaha specialty cake business.

Fischer was elected to the Senate in 2012 after defeating two higher-profile Republicans — Attorney General Jon Bruning and State Treasurer Don Stenberg — in the primary. She went on to defeat Democrat Bob Kerrey, a former governor who was running for his old Senate seat, by nearly 16 percentage points.

