Candidates: Rep. Jared Golden (D) v. Austin Theriault (R), member of the Maine House of Representatives

Ad spending since Labor Day: $10.8 million for Democrats; $10.3 million for Republicans

Past results: Golden defeated former Rep. Bruce Poliquin (R) under the state’s ranked-choice voting system, 53.1 percent to 46.9 percent.

2020 presidential result: 45.5 percent Biden; 51.6 percent Trump

Cook Political Report rating: Toss-up

Some background: Golden came to Congress in 2019 after flipping this rural Maine seat that former President Donald Trump carried handily in 2016 — and benefiting from the state’s newly implemented ranked-choice voting system. He actually trailed his opponent, then-Rep. Bruce Poliquin (R-Maine), after the first round of voting but the allocation of second preferences from third- and fourth-place finishers put him over the top. Golden has stressed his centrist, pragmatic legislating approach throughout his time in office, often unapologetically breaking with his party. (An oft-cited example: opposing an initial version of the climate change and social spending package.)

The state of play: Polling has been sparse, though an October internal poll for the NRCC gave Theriault a two percentage point lead over the incumbent — 47 to 45 percent with nine percent undecided and no ranked-choice simulation. Trump is widely expected to carry the Second District (and its lone Electoral College vote) again, in which case Golden would need to outrun the top of the ticket to hold on.

One thing the incumbent has: plenty of cash. He raised $1.8 million the last quarter and has $3.3 million on hand. Theriault raised $1.1 million during the same period and has around $900,000 for the final sprint to Election Day.

Why you should care: Golden’s candidacy tests the proposition that voters are willing to split their tickets — and want to continue to reward those who push for bipartisan compromise. As one of the co-chairs of the centrist Blue Dog Coalition, a loss by the incumbent would further erode the ranks of House dealmakers.

More on the candidates: Both men have compelling personal histories. Golden is a Marine Corps veteran, once worked for Maine GOP Sen. Susan Collins and served in the Maine House of Representatives before coming to Congress. He’s also no stranger to competitive elections, having emerged victorious three times before.

Theriault, just 30, is a former professional stock car racing driver who now serves in the Maine House of Representatives representing the far north community of Fort Kent. (It’s right on the Canadian border and about a five-hour drive from Portland.) He’s been endorsed by Trump and the entire House GOP leadership slate.

The issues: Guns are an unusually potent issue in the contest. Golden called on Congress “to ban assault rifles” after a deadly mass shooting in Lewiston that killed 18 people — a position Theriault has repeatedly hammered during the campaign. During a recent debate, the incumbent said his comments on assault weapons “came right from the heart” and that “we would have more people alive today” if the mass shooter didn’t have access to assault weapons.

Every day POLITICO will highlight one race to watch. Yesterday’s: Wisconsin Senate.