Six of the eight House Republicans running for the Senate on Thursday voted against the budget deal from Rep. Paul Ryan (R-Wis.) and Sen. Patty Murray (D-Wash.).
Rep. Steve Stockman (R-Texas), who just announced a primary challenge to Sen. John Cornyn (R-Texas), also voted against the bill.
Voting against the deal could help the candidates with the conservative base and with the Tea Party groups that vocally opposed it.
The only Republicans running for the Senate who backed the budget bill were Rep. Bill Cassidy (R-La.), who is seeking to challenge Sen. Mary Landrieu (D-La.), and Rep. Shelley Moore Capito (R-W.Va.), running for an open seat.
The vast majority of House Republicans voted for the plan, handing a big win to both Ryan and Speaker John Boehner (R-Ohio).
The bill passed overwhelmingly, with 332 votes in favor, including 169 Republicans. Only 62 Republicans broke with party leaders and voted against it.
Daines, who's running for an open seat in Montana and is seen as closer to the establishment than the Tea Party, praised Ryan and Murray but said the deal relied too much on future cuts.
"While I'm encouraged by ongoing efforts to develop bipartisan proposals and commend Chairman Ryan and Chairman Murray for their work to find agreement, I am concerned that this budget proposal does not provide Montanans with a much-needed solution to our debt crisis," he said in a statement.
"Rather than taking serious and needed steps to address Washington's spending addiction and growing debt, this budget relies largely on spending cuts many years from now to offset immediate spending increases."
Cotton, a Tea Party favorite who is running against Sen. Mark Pryor (D-Ark.), slammed the budget agreement.
"This budget deal busts the spending caps that took effect just months ago by spending billions now in exchange for supposed long-term spending cuts," he said in a statement. "Arkansans are tired of the Washington ‘long term,' which never seems to arrive."
Broun, a hard-charging conservative, was even more critical of the bill.
"Instead of taking the opportunity to enact meaningful spending reform, this deal spends an additional $63 billion over the next two years in exchange for the empty promise of spending cuts in the future — a budget gimmick which is all but certain to be cancelled before any real cuts come to fruition," he said in a statement.
"We must stop spending money we don’t have while kicking the tough decisions down the road."
Among Democrats running for the Senate, Reps. Gary Peters (D-Mich.) and Bruce Braley (D-Iowa) voted for the deal. Rep. Colleen Hanabusa (D-Hawaii), who is challenging Sen. Brian Schatz (D-Hawaii) in a Democratic primary, was one of 32 Democrats to vote against it.