Participation in Maine's delegate selection process is open to all registered voters who are enrolled in the Republican Party. Residents who are enrolled in another party must change their affiliation at least 15 days before the primary. A resident who is unregistered or not enrolled in any party may register to vote on the day of the primary.

Tuesday 5 March 2024 (presumably): Maine Primary. Hours reportedly 6:00a-8:00p EST (1100-0100 UTC). Voting places open between 6:00a Eastern Time and 10:00a Eastern Time depending on the size of the town. Delegate Binding: Winner-Take-Most Primary. Voter Eligibility: Closed Primary.

Primary (preliminary)
Included in Nationwide vote.

All 20 of Maine's delegates to the Republican National Convention are pledged to presidential contenders in today's Maine Presidential Primary. [Rules of the Maine Republican Party 5.0]

• Statewide primary results will determine the number of delegates each candidate receives to the national convention. The party will use the 1st round of voting to allocate delegates. If any one candidate receives more than 50% of the vote, that contender receives all of Maine's delegates. [Rules of the Maine Republican Party 5.2(b)]
• Otherwise, delegates will be allocated to candidates who receive 20% or more of the vote; if no candidate receives at least 20% of the vote, the threshold is reduced to 5% of the vote. [Rules of the Maine Republican Party 5.2(a)]
• Starting with the candidate who received the most votes, the candidate's vote is multiplied by the total number of delegates and divided by the total number of votes cast for all candidates receiving in excess of the threshold. The result is rounded up to the next whole number. Repeat the process for each remaining candidate in descending order until all delegates are allocated. [Rules of the Maine Republican Party 5.2(c)] Sections 5.2(c) and (d) use conflicting rounding formulas.
• The proportional delegate allocation shall be rounded to the nearest whole delegate. In the event that a delegate is unallocated due to rounding, the unallocated delegate vote shall be cast in favor of the candidate closest to the rounding threshold. In the event that delegates are over-allocated due to rounding, the over-allocated delegate shall be removed from the candidate furthest from the rounding threshold. [Rules of the Maine Republican Party 5.2(d)] Sections 5.2(c) and (d) use conflicting rounding formulas.

Primary (preliminary)

Delegates are bound for the 1st ballot. If a Presidential candidate withdraws, the delegates bound to that candidate become unbound. [Rules of the Maine Republican Party 5.2(e)]

• 6 district delegates are elected by caucus participants-- 3 from each of Maine's 2 Congressional districts.
• 11 delegates are elected by the Maine State Convention as a whole.
• 3 party leaders, the National Committeeman, the National Committeewoman, and the chairman of the Maine's Republican Party, will attend the convention as bound delegates by virtue of their position.