A Democratic governors group backing Gov. Janet Mills’ reelection campaign is reserving $5 million in television advertising, underscoring what's expected to be a hard-fought and costly battle.

The Democratic Governors Association announced its television ad buy reservation on Wednesday. The Maine Republican Party previously announced nearly $4 million in TV ad bookings for the race.

With Mills and her opponent, former Republican Gov. Paul LePage, having raised a combined $4 million, there will be no shortage of cash, said Mark Brewer, political science professor at the University of Maine.

“They’ll have money to do whatever they want to do,” Brewer said. “Neither side is going to run short of funds.”

The DGA announcement came a day after Mills and LePage reported their latest fundraising numbers.

The Mills campaign raised another $1.1 million since Jan. 1, bringing her total to $2.7 million, and extending her cash advantage over the LePage campaign, which has raised a total of $1.3 million to date.

The large fundraising hauls point toward this possibly being the most expensive governor’s race in Maine history.

It's shaping up to be the first two-way race for LePage, who has never collected a majority in his previous, multi-candidate races. So far, no big-name independents have entered the current race.

It's also shaping up to be a difficult election cycle for Democrats, especially with inflation at its highest rate in years.

One wild card is the leaked draft Supreme Court opinion suggesting the Roe v. Wade precedent legalizing abortions could be overturned, Brewer said.

That news could mobilize some voters to support Mills, who has vowed to protect a woman's right to reproductive health care, Brewer said.