DENVER – One month before Election Day, a federal appeals court has temporarily blocked a lower-court ruling that would have allowed unlimited campaign dollars to flow into state-level campaigns in Montana.

The decision from the Ninth Circuit Court of Appeals came late on Tuesday, one week after a federal judge in Montana struck down that state’s limits on campaign contributions as an unconstitutional restriction of free-speech rights.

Although Montana and its three reliably Republican electoral votes have been largely overlooked in this year’s presidential race, the state has become a pitched battleground over campaign-finance rules. In June, the Supreme Court tossed out a Montana law that banned corporate contributions to candidates and political parties.



The Ninth Circuit appeals court, which oversees much of the Western United States, said it was staying the lower court’s ruling until the judge, Charles C. Lovell, provided a fuller explanation behind his reasoning.

The judge’s original ruling landed in the middle of a fiercely competitive election season in Montana, and has the potential to gut many limits on donations to candidates for state-level positions. Under the Montana law now being challenged by conservative political groups there, individuals and political committees could give only $630 to candidates for governor or lieutenant governor, and as little as $160 for other candidates for public office.

Judge Lovell said the rules prevented candidates from raising enough money “for effective campaign advocacy.”

For now, the old rules have been reinstated, with uncertain implications on races for an open governor’s seat and the statehouse.

“The effect is hard to measure because, well, the status quo has been returned,” David C. W. Parker, a political science associate professor at Montana State University, said in an e-mail. “I would say that outside groups haven’t been hugely active on broadcast television on the races for state offices. They seem to have been active in other way — mailers and such, but this is hard to elevate fully.”

The ruling did not affect the tight Senate race between Jon Tester, the Democratic incumbent, and Representative Denny Rehberg, his Republican challenger. That contest, which could tilt the balance of the Senate, has been swamped by millions of dollars of spending from local donors and outside interest groups.