FILE - This combination of images shows from left, U.S. Sen. Jon Tester, and opponent, Republican Montana Senate candidate Tim Sheehy, during a debate in Missoula, Mont., on Sept. 30, 2024. (Ben Allan Smith/The Missoulian via AP, File)

U.S. Sen. Jon Tester, a Democrat from Montana seeking re-election to a fourth term, is seen at a campaign rally in a hotel ballroom, Oct. 25, 2024, in Bozeman, Mont. (AP Photo/Matthew Brown)

People wait in line to vote outside a polling place on Election Day at MetraPark, Nov. 5, 2024, in Billings, Mont. (AP Photo/Matthew Brown)

A Yellowstone County election worker places a ballot into a box at MetraPark on Election Day, Tuesday, Nov. 5, 2024, in Billings, Mont. (AP Photo/Matthew Brown)

FILE - U.S. Senate candidate Tim Sheehy talks about his campaign, Friday, Feb. 9, 2024, in Helena, Mont. Sheehy is seeking the Republican nomination to challenge U.S. Sen. Jon Tester in the November election. (AP Photo/Matthew Brown, File)

People fill out ballots during Election Day at MetraPark, Nov. 5, 2024, in Billings, Mont. (AP Photo/Matthew Brown)

People fill out ballots during Election Day, at MetraPark, Tuesday, Nov. 5, 2024, in Billings, Mont. (AP Photo/Matthew Brown)