With Gov. Janet Mills’ withdrawal Thursday morning, the Senate race in Maine now appears to be a competition between incumbent Sen. Susan Collins, a Republican, and Democratic newcomer Graham Platner.

The Democratic primary takes place in June, and Platner will have to beat David Costello for his party’s nomination, but he’s almost certain to do so. That means Mills’ announcement turns our attention to November’s midterm election.

Here’s how Platner and Collins compare by the numbers, endorsements and track records:

POLITICAL EXPERIENCE

Collins, who is currently in her fifth term, was first elected to the Senate in 1996.

During that time, she has risen through the chamber’s ranks to now chair the powerful Senate Appropriations Committee. She routinely champions the federal spending she has secured for Maine.

At times, she has broken with or criticized President Donald Trump. At the outset of the U.S. conflict with Iran, when Trump threatened to destroy an entire civilization, she said the president was using “incendiary language.”

But critics have contended that she has largely voted along party lines on issues ranging from approving funding for Immigration and Customs Enforcement to confirming conservative Supreme Court justices like Brett Kavanaugh.

Platner, meanwhile, has never held an elected office.

He served as a United States Marine and was deployed to Iraq, later enlisting in the U.S. Army to serve in Afghanistan.

After his time in the military, he took over an oyster farm off the coast of Sorrento.

BIG ENDORSEMENTS

Collins carries endorsements from heavy-hitting Republicans like Senate Majority Leader John Thune of South Dakota and Tim Scott of South Carolina, chair of the National Republican Senatorial Committee.

Trump has gone back and forth in his characterization of Collins, and he has not formally endorsed her. In a March television appearance, he included her among a group of Republicans he was “not at all fans of,” before calling her a “good person” and saying that he hopes she wins.

Collins has also received widespread support from Republicans within Maine. Some of that enthusiasm was on display over the weekend at the state GOP’s convention — where the senator tossed hats into a high-energy crowd.

Earlier this month, former Democratic Sen. Joe Manchin of West Virginia endorsed Collins for 2026, saying that “if you lose a Susan Collins in the United States Senate, you’ve lost the soul of America.”

Platner has secured a long list of endorsements from national progressive groups like College Democrats of America and David Hogg’s Leaders We Deserve, as well as local outfits like the Maine People’s Alliance and the Maine State Nurses Association. He has campaigned alongside Troy Jackson, the former Maine Senate president who is running for governor.

Platner also announced a slew of new Maine endorsements Thursday, just hours after Mills withdrew from the race.

On the national level, he’s also been backed by Democratic Sen. Elizabeth Warren of Massachusetts and independent Sen. Bernie Sanders of Vermont, who reiterated his support in a Thursday post on X.

FUNDRAISING

Collins has significantly more cash available, according to the latest filings with the Federal Elections Commission.

Collins had just over $10 million on hand at the end of March, according to her campaign’s FEC records.

Platner had about $2.7 million at that same time, according to the FEC.

Those figures are updated quarterly, so the latest numbers will come out in July.

AD SPENDING

Platner’s campaign has spent more on advertising than Collins’, but those figures may not show the full picture.

Platner for Maine had spent about $7.3 million on ads as of Thursday afternoon, according to the ad tracking site AdImpact. Collins for ME Senate had spent about $2.4 million.

But super PACs backing Collins have spent at least $50 million altogether. Meanwhile, Majority Forward, a super PAC backing Democrats in races across the country, has spent about $4.7 million on ads criticizing Collins.

SOCIAL MEDIA FOLLOWINGS

Collins has about 102,000 followers on her Facebook page, plus about 36,000 on her campaign-specific page, which calls her the “#1 Most Bipartisan Senator.”

Platner’s page — which frames him as a “Friend of the working Mainer, foe of the oligarchy” — boasts about 148,000 followers.

On Instagram, Collins’ roughly 25,000 followers falls well short of Platner’s roughly 322,000.

But on X, formerly known as Twitter, Collins’ main page has more than half a million followers, versus Platner’s roughly 90,000.

BETTING MARKETS GIVE THE ODDS

Prediction markets, platforms that allow users to place bets on the outcome of real-world events, have emerged as an increasingly significant metric in recent months. Odds are based on the total amount of money bet on an outcome.

Proponents argue they’re more reliable than traditional polls, since respondents have a financial stake in the outcome they predict. Critics argue that the markets are effectively gambling, and they create new risks for insider trading and market manipulation.

Shortly after noon Thursday, the prediction market Polymarket had the odds of a Democrat winning the Senate seat at 72%, with Republican victory pegged at 28%. The Republican odds ticked up from after Mills dropped out compared to the day before. In all, users had wagered just over $61,000.

Kalshi, another platform, had the odds at 68% to 32% in favor of a Democratic victory Thursday afternoon. The odds of a Democratic victory had peaked at nearly 73% earlier in the week. That pool is larger, with more than $315,000 wagered in total.

AGE

Collins is 73.

Platner is 41.

They’re both younger than Mills, who at 78 would have been the oldest freshman senator in history.