WASHINGTON (AP) - Montana voters head to the polls Tuesday in the state primary to pick nominees replacing outgoing Republican officeholders for the U.S. Senate and House, though one prominent contender will not appear on the ballot. At the same time several state legislative primaries will underscore internal divisions inside Montana's leading Republican Party.

Republicans maintain narrow edges in both houses of Congress. Montana has not ranked high among targets Democrats aim to capture to reclaim either chamber, yet the open seats create an opening for someone to tap into the state's independent leanings.

Republican U.S. Sen. Steve Daines is not pursuing another term. He has backed former U.S. Attorney Kurt Alme as his successor. Daines' decision to step aside late in March and Alme's entry into the race, both occurring right before the filing cutoff, looked coordinated. President Donald Trump reinforced that impression when he endorsed Alme.

"In fact, if Kurt didn't have the highest level of aptitude and talent, Steve would have remained exactly where he is…." Trump said in a social media post.

Alme also carries support from the state's other leading Republicans, U.S. Sen. Tim Sheehy and Gov. Greg Gianforte. He competes against Republicans Lee Calhoun and Charles Walking Child for the nomination.

The Democratic side features former state Rep. Reilly Neill, whose fundraising totals five times the combined amount raised by her four primary opponents.

The primary winners will square off against former University of Montana president Seth Bodnar, who is running without party affiliation. As of mid-May, Bodnar had raised more money than all other candidates combined. Bodnar belongs to a small group of independents who skipped the primary process and may affect the general election for certain Republican incumbents.

In the 1st Congressional District, Republican U.S. Rep. Ryan Zinke is not seeking a fourth full term because of health issues. He, Trump, Sheehy and Gianforte have endorsed talk radio host and former Zinke staffer Aaron Flint over Montana Secretary of State Christi Jacobsen, former state Sen. Al Olszewski and former high school government teacher Ray Curtis. The Democratic field includes former gubernatorial candidate Ryan Busse and union organizer Sam Forstag.

Inside the state Legislature, several primaries reveal ongoing tensions among Montana Republicans.

Early in the 2025 legislative session, nine Republican state senators broke with the party on important floor votes, effectively giving Democrats control of the chamber.

State Sen. Shelley Vance of District 34 is the only one of those maverick lawmakers, labeled the "Nasty Nine" by the Montana GOP, who faces reelection in 2026. Two others, state Sens. Jason Ellsworth and Bruce Gillespie, chose instead to run for the state House in Districts 34 and 18. The remaining six are either term-limited, retiring or not on the ballot this cycle.

After the revolt, the Montana Republican Party issued a list of preferred state legislative candidates, including some who are challenging Republican incumbents in the state House. Yet some of those selections created friction with Gianforte, who has posted a series of social media videos appearing alongside four state House incumbents opposed by the party.

The governor voiced support for state House Speaker Brandon Ler and state Reps. Valerie Moore and Ken Walsh, all seeking reelection, plus state Rep. Eric Albus, who is running in state Senate District 14. Gianforte stops short of formal endorsements in the videos, but he described one lawmaker as a "great partner" and said he was "proud of the work" he had done with another.

Half of the state's 50 state Senate seats and all 100 state House seats are on the ballot in 2026.

Here are some of the key facts about the election and data points the AP Decision Team will monitor as the votes are tallied.

When do polls close?

Polls close at 8 p.m. MT, which is 10 p.m. ET.

What's on the ballot?

The AP will provide vote results and declare winners in contested primaries for U.S. Senate, U.S. House, Public Service Commission, state Senate and state House.

Who gets to vote?

Any eligible voter may participate in any party's primary.

How many voters are there?

As of May 25, there were about 791,000 registered voters in Montana. Voters do not register by party.

How many people actually vote?

About 190,000 Republican primary votes and about 108,000 Democratic primary votes were cast in the 2024 U.S. Senate primaries.

How much of the vote is cast early or by absentee ballot?

About 68% of the 2024 primary vote was cast before primary day.

As of Friday, about 166,000 ballots had already been cast in Tuesday's election.

When are early and absentee votes released?

Counties vary in how they release votes. In previous elections, results from absentee voting mostly were released along with in-person Election Day voting throughout the night. About two-thirds of Montana's 56 counties tend to release all or almost all of their mail and in-person early voting results in the first vote update of the night, often along with results from in-person Election Day voting. About half the counties tend to release all or almost all their in-person Election Day results in the first vote report.

How long does vote-counting usually take?

In the 2024 U.S. Senate primary, the AP first reported results at 10:26 p.m. ET, or 26 minutes after polls closed. The last vote update of the night was at 4:06 a.m. ET with about 84% of total votes counted.

When will the AP declare a winner?

The Associated Press does not make projections and will declare a winner only when it is determined there is no scenario that would allow a trailing candidate to close the gap. If a race has not been called, the AP will continue to cover any newsworthy developments, such as candidate concessions or declarations of victory. In doing so, the AP will make clear that it has not yet declared a winner and explain why.

How do recounts work?

Montana requires an automatic recount only in the event of a tie vote. A candidate may request a recount if the margin is less than 0.5% of the total vote, but the state will only pay for it if the margin is 0.25% or less. The AP may declare a winner in a race that is subject to a recount if it can determine the lead is too large for a recount or legal challenge to change the outcome.

Are we there yet?

As of Tuesday, there will be 154 days until the 2026 midterm elections.

- Robert Yoon, Associated Press