Oregon has been controlled by Democrats for decades but a combination of factors has Republicans thinking they could increase their political power.

The presence of a third-party candidate combined with the unpopularity of outgoing Democratic incumbent Kate Brown makes this governor’s race among the hardest to read in the country. Democratic nominee Tina Kotek is facing a stiff challenge by GOP candidate Christine Drazan with Democrats worried that unaffiliated candidate Betsy Johnson will siphon off enough votes from Democrats to give Drazan the win.

Oregon’s 5th Congressional District is also a toss-up. The district, which was significantly redrawn, hasn’t been held by a Republican in a quarter-century. But district boundary changes and the primary defeat of an incumbent centrist by progressive Jamie McLeod-Skinner have created opportunity for GOP candidate Lori Chavez-DeRemer.

Oregon’s newly created 6th Congressional District appears safer for Democrats. The district, which Oregon gained based on population growth, was drawn by the Democratic-controlled Legislature and includes the state capital Salem and parts of Portland’s affluent southwestern suburbs. Democrat Andrea Salinas, a state representative, is contesting the seat against Republican Mike Erickson, a businessman who’s running for Congress for the third time.

In a ballot measure, Oregon voters are being asked to decide whether the state should be the first in the nation to amend its Constitution to explicitly declare that affordable health care is a fundamental human right. In another ballot measure, Oregonians will decide whether people wanting to purchase a gun will first have to qualify for a permit. The measure would also ban large capacity magazines over 10 rounds.

Here’s a look at what to expect on election night:

ELECTION NIGHT

Most polls close at 8 p.m. local time (11 p.m. ET). Malheur County is mostly in the Mountain Time Zone, where polls close at 10 p.m. ET.

HOW OREGON VOTES

Oregon votes by mail. Voters can also leave ballots in drop boxes. Ballots must be received by county elections offices by 8 p.m. on Election Day. If mailed, ballots must be postmarked by Election Day.

Returns will start coming out soon after 8 p.m. but it could take days for close races to be decided.

DECISION NOTES

The AP will count votes and declare winners in 83 contested elections in Oregon, including three statewide races and six U.S. House races. In the 2020 general election, the AP reported initial results at 11 p.m. ET.

The AP may call a statewide or U.S. House race in which the margin between the top two candidates is 0.5% or less, if we determine the lead is too large for a recount to change the outcome.

The AP will not call down-ballot races on election night if the margin between the top two candidates is less than 2% or if the leading candidate is within 2% of the 50% runoff threshold. The AP will revisit those races later in the week to confirm there aren’t enough outstanding votes left to count that could change the outcome.

WHAT ELSE SHOULD I KNOW?

Q: WHAT’S CHANGED SINCE THE PANDEMIC ELECTION OF 2020?

A: In 2020, mailed ballots had to be received by county election offices by 8 p.m. on Election Day. A 2021 law requires only that ballots be postmarked by Election Day.

Q: WHAT DO TURNOUT AND ADVANCE VOTE LOOK LIKE?

A: Nearly 66,000 advance ballots had been received in this all-mail state as of Oct. 25. That’s only about 3% of the advance turnout in 2018, but these numbers often spike in the days before Election Day.

Q: HOW LONG DOES COUNTING USUALLY TAKE?

A: In 2020, it took until around 2 p.m. on Friday, three days after Election Day, for 90% of ballots to be counted.

Q: WHAT HAPPENS AFTER TUESDAY?

A: In Oregon, a voter who lives in one county can return a ballot to a drop box in a different county. On the day after the election, county clerks do “ballot swaps” to exchange ballots they receive from other counties so they can be counted in the correct jurisdiction. This is what accounts for some of the missing vote on election night. Also, the change in the law that allows votes to be counted if they were postmarked by Election Day (and received later) could delay counting of some votes.