At least nine candidates will be in the race for retiring Sen. Olympia Snowe's (R-Maine) Senate seat, according to a count by The Hill, including six Republicans, two Democrats and an independent.

The six Republicans had all filed the requisite 2,000 signatures by midday Thursday, the last day for candidates to officially enter the race. Those Republicans included state Attorney General William Schneider, Maine Secretary of State Charlie Summers and state Treasurer Bruce Poliquin.

One Democrat, former Maine Secretary of State Matthew Dunlap, has also filed, according to Maine officials.

State Sen. Cynthia Dill, another Democrat, told The Hill on Wednesday she had racked up more than 2,000 certified signatures and would file them by the end of the day on Thursday.

But all eyes are on Angus KingAngus Stanley KingFor .2 billion, taxpayers should get more than Congress’s trial balloons Overnight Health Care — Sponsored by PCMA — Trump hits federally funded clinics with new abortion restrictions Dem senators ask drug companies to list prices in ads MORE, the independent former governor who left both Democrats and Republicans unsure of how to proceed when he announced last week he would make a bid for the seat. Early polling showed King leading a three-way race for the seat.

Because he isn't running for the nomination of one of the two major parties, King has until June 1 to collect and file signatures. But he also has a bigger task: Independent candidates must assemble double as many signatures as partisan candidates. 

King spokewoman Crystal Canney said the campaign was in its early stages but that the petition process has gotten off to a solid start.

Due in part to King's decision to run for Snowe's seat, no top-tier Democratic candidates announced plans to seek the seat. Maine Reps. Michael Michaud and Chellie Pingree both considered it but both eventually opted against a run.

Senate Democrats say they are waiting to see how the race shapes up before making any decisions about whether to back King — who has yet to say which party he would caucus with — or to actively support a Democratic candidate. But Maine Democrats say they aren't ceding the race to King and will mount a competitive bid for the seat.