PORTLAND, Maine (AP) — Republican U.S. Sen. Susan Collins and Democratic challenger Sara Gideon clashed Wednesday night over attack ads, health care and the judiciary in their final debate before Election Day.

Gideon, speaker of the Maine House, sought repeatedly to link Collins with Senate Majority Leader Mitch McConnell and President Donald Trump, urging Mainers to vote for change.

Collins, chief architect of the Paycheck Protection Program that helped 250,000 Mainers, told voters she's been hard at work during the pandemic while Gideon adjourned the House seven months ago.

On health care, Collins said the proposed public health option supported by Gideon would cause many rural hospitals to close, while Collins said she cast the deciding vote to spare the ACA and protect people with preexisting conditions.

“These are the facts. Not even millions of dollars and misleading ads will change that,” the senator said.

Gideon accused Collins and McConnell of undermining the Affordable Care Act with no plan for a replacement.

“They spent 10 years trying to take the Affordable Care Act from you,” she said of Republicans.

It was the fifth and final debate. Unlike the previous debates, this one featured only the two leading candidates squaring off one-on-one near the end of a costly race that could help determine which party controls the Senate. Polls suggest a tight race.

The event came just days after Collins voted against the president's latest Supreme Court nominee, Amy Coney Barrett. Collins said she did so not based on Barrett's qualifications, but based on fairness, since Republicans denied an election year vote on one of President Barack Obama's nominees.

Gideon used Trump's judicial appointments to attack Collins on women's reproductive rights, and on health care. Collins noted that her opponent declined to say whether she'd support packing the Supreme Court with additional justices. Collins wants to keep the court at nine.

Both candidates also accused the other of running misleading ads.

More than $120 million will have been spent on TV advertising by Election Day, according to the ad tracking company Kantar/CMAG. That doesn’t include the tens of millions still pouring into the state.

As in the past, Gideon pointed out that Collins hasn't said whether she'll vote for Trump. Collins did not vote for Trump in 2016, but wrote in another Republican.

The moderator, Steve Bottari, pointedly asked Collins if Trump deserved to be reelected to another four-year term.

“I’m not getting into presidential politics," Collins said, repeating her position that she can work with a Trump administration or with the administration of former Democratic Vice President Joe Biden if he wins the election.

“What I don’t want to see," Collins said, "is one party control in Washington, because I think that would lead to a far-left agenda being pushed through the Congress.”

About 400,000 Maine voters already had cast absentee ballots as of Tuesday, and ranked choice voting will be used in the tallies.

Under the ranked voting system, voters can rank all candidates in order of preference on their ballots. If no one wins the majority of first-place votes, then there are additional tabulations, aided by computers, in which last-place candidates are eliminated and votes reallocated.

The debate, sponsored by WMTW-TV, was different from four previous debates because independents Lisa Savage and Max Linn weren’t invited.

But the independents didn’t go quietly. They filed a formal complaint with the Federal Elections Commission over the snub.

WMTW-TV said the invitations were based on a "good faith journalistic judgement" based on objective criteria approved by legal counsel.