BOISE, Idaho (AP) — Republican U.S. Rep. Mike Simpson has swept aside challenges from within his own party in primaries and then Democratic contenders in general elections to retain his seat in Congress representing the state's 2nd Congressional District for two decades.

The 70-year-old Simpson appears poised to do so again on Tuesday in red-state Idaho.

He's trying for a 12th term. He's up against Democrat Aaron Swisher, an economist and former Micron Technology, Inc. employee who says his primary goal is to create a better deal for working-class Americans. Simpson defeated Swisher two years ago, making this a rematch.

Swisher, who backs a universal, single-payer health care system, says the economy's structure means even people with college degrees and two-income families are having trouble.

Simpson has consistently voted to end the Affordable Care Act. He serves on the House Appropriations Committee as well as a key subcommittee involving energy. He's helped bring in millions of federal dollars for the Idaho National Laboratory, one of the nation’s primary nuclear research labs.

He's also known for cobbling together support among environmentalists, ranchers and local governments in 2015 to create three wilderness areas in central Idaho that combined protect some 463 square miles (1,200 square kilometers). It was signed into law by President Barack Obama.

U.S. Rep. Russ Fulcher is seeking a second term in the 1st Congressional District, last held by a Democrat in 2011. Democrat Rudy Soto, who served nine years in the Army National Guard, will try to change that.

Fulcher served in the Idaho Legislature, where he was known as among the more far-right leaning members. He has bachelor’s and master’s degrees in business from Boise State University.

Fulcher for years had his eyes set on becoming governor. He narrowly lost to then-Gov. C.L. “Butch” Otter in the 2014 Republican primary despite winning all three of Idaho’s most populated counties — all of which are in the 1st Congressional District.

Soto, the son of a Mexican immigrant, has a platform that includes affordable health care coverage for everyone, backing environmental protections and holding corporate polluters accountable. He also promises to seek more funding for Idaho roads and schools.