(CNN) -- Green Party candidates for key congressional races will likely not appear on Montana ballots this fall after the US Supreme Court declined Tuesday to take up an emergency petition from the state's Republican secretary of state.
The decision could have a major impact on a competitive US Senate race between Republican incumbent Sen. Steve Daines and Democratic Gov. Steve Bullock.
Justice Elena Kagan issued the order on Tuesday without comment or recorded dissent. CNN has reached out to Montana Secretary of State Cory Stapleton's office for comment.
Stapleton filed an emergency request Monday urging the high court to place a hold on proceedings pending further legal action after lower courts had approved the Green Party's absence from the ballot.
Montana Republicans earlier this year backed an effort to qualify the Green Party, which has traditionally drawn some liberal voters from the Democrats, for the ballot. But after that was revealed, state Democrats urged enough people who signed petitions to disavow their support.
The secretary of state's office, however, did not accept requests to remove their support, so the state Democrats and several people sued. A lower court judge and the state Supreme Court sided with the Democrats, saying the Green Party no longer qualified for November's contest.
The Senate race in Montana is expected to be a tight contest, garnering national attention as a potential part of Democrats' efforts to retake the chamber. Labeleda toss-up race by Inside Elections with Nathan L. Gonzales, who is a CNN contributor, it is among half a dozen such seats that Democrats are targeting in hopes of netting the four they would need to ensure control of the chamber if they don't win the White House.
And it isn't the only competitive Montana campaign that could be affected by a Green Party presence or lack thereof. The race for Montana's at-large US House seat was decided by fewer than 5 points in 2018 and is again competitive this year. Democrats hoped that keeping the Green Party off the ticket would be good news for their repeat congressional nominee, Kathleen Williams.
While the Supreme Court's action Tuesday doesn't seal off the possibility of the Green Party appearing on the ballot, it puts pressure on the effort's timeline.
Stapleton noted in the petition Monday that the state must print ballots soon, and without immediate action, he argued, they won't include Green candidates. That print date is approaching -- according to Montana law, election administrators must send ballots to absent military and overseas electors by September 18.