Graham Platner speaks during the Maine Democratic Party's convention in Portland in May. (Shawn Patrick Ouellette/Staff Photographer)

Maine Democrats on July 25 will hold a nominating convention where delegates from around the state will come together to select a U.S. Senate candidate to replace Graham Platner.

The convention will be held in Bangor and will include 601 delegates comprised of state committee members and representatives selected at county meetings. Candidates will be able to make speeches at the convention, after which the delegates will vote in rounds.

The first steps in the unusual process were made public by the Maine Democratic Party on Friday night, a few hours after Platner, who won Maine’s Democratic primary for Senate in June, officially withdrew from the race.

Platner faced calls to drop out after a former girlfriend accused him of sexual assault in a Politico story — the latest in a series of scandals that have plagued his campaign since last year.

His decision to withdraw, which he announced Wednesday night, sent the party into a frantic effort to develop the process for finding a replacement to take on U.S. Sen. Susan Collins.

Here’s what that process will look like.

Why are Democrats able to pick a new candidate?

According to state law, if a candidate nominated in a primary election — as Platner was — withdraws on or before 5 p.m. on the second Monday in July — July 13 this year — a replacement can be named. Platner officially submitted paperwork to withdraw from the race Friday.

The law gives a deadline of the fourth Monday in July — July 27 this year — for the party to make its replacement nomination, and largely leaves the selection process up to the party.

The Democratic Party’s charter addresses the process for naming replacements, but also doesn’t go into great detail, so the party started working quickly to develop criteria this week.

The charter says only that a nominating meeting should be called by a person appointed by the party chair, and that the meeting should be run in accordance with state law, the party charter and other applicable rules.

It also says the party should coordinate with county committees and notify them of the meeting.

When and where will the convention be held?

The party announced Friday that the convention will be held at 9 a.m. on Saturday, July 25, at the Cross Insurance Center in Bangor.

The chair of the party, or their designee, will preside over the convention.

Who are the delegates that will select the next Senate candidate?

The 601 delegates at the convention will be comprised of 101 state committee members and 500 county delegates (not including 100 alternates) from Maine’s 16 counties.

Each county will be apportioned one-third the number of delegates it received for the 2026 convention, where delegate numbers were based on turnout in the 2024 primary.

The state committee is the governing body of the party. Its members are elected at the biennial state convention and represent every county in Maine.

Delegate nominating meetings will be held the weekend of July 18 and 19 in all 16 counties, either in-person or virtually, as determined by each county chair, according to procedures released by the state party.

The date, time and location of each meeting will be announced by Wednesday and will be advertised via email, social media and press release. Those interested in participating can also check the state party website for updates.

Counties will administer one round of voting at the meetings, either by paper ballot or electronically. The people with the most votes will become delegates.

People interested in serving as delegates must pre-register by Wednesday, July 15, at 5 p.m. on the Democratic party’s website.

Those looking to participate in county meetings are also being asked to pre-register on the party’s website, though submission of the pre-registration form is not required to participate.

Each candidate will have an opportunity to make a five-minute speech, and will be allowed to have a supporter give a two-minute speech on their behalf.

Voting will be done by ballot and will take place in rounds, similar to Maine’s ranked-choice system. The first round will include every candidate certified to participate. If no candidate receives a majority of votes, the top five candidates will proceed to the second ballot. (Unlike in ranked-choice voting, the second round will not be counted in an automatic runoff. It will be a new, separate vote.)

If no candidate receives a majority in the second round of voting, then the last-place candidate is eliminated and another vote is held, with the process repeating until one candidate receives a majority.

What is the criteria for candidates?

Candidates must submit written declarations of intent, including summaries of their visions for their campaigns, to the party by 5 p.m. Wednesday. The party has said nominations will not be accepted from the floor.

In addition, candidates will need to gather at least 500, and no more than 1,000, valid signatures from voters who were registered as Democrats as of the June 9 primary. At least eight counties — half of Maine’s 16 counties — must be represented in the 500 signatures.

Signatures are due by 11:59 p.m. on Monday, July 20.

The party will validate the signatures and notify candidates that they have qualified for the nominating convention.

Who are the candidates?

More than a half dozen candidates have already said they plan to run for Senate. They include three of the five candidates who competed in the Democratic primary for governor, including runner-up and former Maine CDC Director Nirav Shah, former Maine Senate President Troy Jackson and Secretary of State Shenna Bellows.

Two candidates who competed in the Democratic primary in Maine’s 2nd District have also gotten in the race: former congressional staffer Jordan Wood, and graduate student and social worker Paige Loud.

Other candidates include Dan Kleban, the co-founder of the Maine Beer Co. in Freeport; David Costello, a former government official in Maine and Maryland who finished a distant third in the June Senate primary; and Andrea LaFlamme, who ran a write-in campaign in the primary.

State Rep. Valli Geiger, D-Rockland, a Platner ally, said on social media this week that she is a “possible candidate,” but has not filed federal campaign finance paperwork as the others have.

Will the public be able to hear from candidates?

The convention will only be open in-person to delegates, credentialed press and staff — and not the public. The party has cited safety reasons and said the proceedings will be livestreamed for the public to watch.