BISMARCK, N.D. (AP) — U.S. Rep. Kevin Cramer's shift to the North Dakota Senate race sets off a Republican scramble for the state's lone congressional seat, including familiar names and a political newcomer.

Cramer's announcement was pushing state Sen. Tom Campbell, one potential GOP candidate, into the House race instead.

But the wealthy potato farmer, who has said he'd be in lockstep with President Donald Trump, has failed to energize much support from party faithful, despite digging deep into his own pocket in recent months to buy advertising to raise his profile statewide. Almost three-quarters of the more than $1 million he has raised has come from himself, Federal Election Commission filings show.

The only other declared GOP candidate in the race is Tiffany Abentroth, who only recently entered the public arena but brings a resume to the race likely to impress voters in the largely agricultural red state.

The single, 32-year-old former U.S. Marine and Iraq war veteran, whose family has farmed in North Dakota a decade before statehood in 1889, believes she will bring a "refreshing change of pace" to Congress.

"I believe to truly have a functional, bipartisan democracy, you have to be able to work with both sides to pass legislation," said Abentroth, who announced her candidacy before Cramer veered to the Senate race. "I believe in honesty and transparency and I think the voters of North Dakota are looking for the same."

The GOP's wild card is state Sen. Kelly Armstrong, a former defense lawyer who heads the state party. Armstrong confirmed Friday that he was "considering" a bid for Congress.

Armstrong also has strong ties to North Dakota's oil industry. His father, Mike, is a longtime oil driller, who has been a competitor, colleague and bird-hunting buddy for decades with billionaire Harold Hamm, considered the godfather of North Dakota's oil industry.

Hamm is the chairman of Oklahoma City-based Continental Resources Inc., which is one of the oldest and biggest oil drillers in North Dakota. The oil tycoon also endorsed Trump and will served as Cramer's finance chairman in his run against Democratic Sen. Heidi Heitkamp in November.

Another potential GOP candidate is Bismarck businessman and former North Dakota Republican Party Chairman Gary Emineth who withdrew his U.S. Senate bid after speculation of Cramer's run for that seat. Emineth said this week he hasn't ruled out a run for House.

Democrats have one declared candidate, Ben Hanson, a commercial real estate broker from Fargo and one-term state representative who lost his seat in 2016.

Hanson said Friday that he did not expect any more Democrats to enter the race. Former Democratic Rep. Earl Pomeroy served as North Dakota's lone congressman for 18 years before losing in 2010 to Rick Berg in his bid for a 10th term in the House. Berg was defeated by Heitkamp in the Senate race two years later by less than 3,000 votes.

Berg said Friday he also hasn't ruled out a run.