Early bellwethers: Key races to watch once polls close on election night

The 2022 midterms are shaping up to culminate in an unpredictable election night, with recent surveys showing close fights in a host of key races that will determine which party controls Congress.

A few points in either direction, within the margin of error in many polls, could be the difference between Democrats overperforming to hold at least one chamber for the next two years — or Republicans running the table with commanding victories.

In the 50-50 Senate, Republicans need a net gain of just one seat to capture the majority. In the House, Republicans have 212 members and need to add six to guarantee a majority.

Here’s a guide to some of the competitive races in which polls close early, which election forecasters say will carry a larger significance in reading the direction of the political environment.

A Democratic stress test

Indiana’s polls are among the first to close, at 7 p.m. ET, and the state’s 1st Congressional District, based in Gary in the northwest, will provide an early glimpse of whether Democrats can hold their own and limit the damage in a tough year.

First-term Rep. Frank Mrvan is running for a second term against Republican challenger Jennifer-Ruth Green. The district tilts toward Democrats by 3 points compared with the country as a whole, and the Cook Political Report, the nonpartisan analysts of elections, moved it from “lean Democrat” to “toss-up” in the summer. If Democrats lose this race, they could be in for a long, rough night.

A defeat for Mrvan could put Republicans on track to pick up 20 or more House seats, Cook’s House editor David Wasserman suggests.

Virginia's three crystal balls

The fates of three House Democrats first elected in the 2018 blue wave will tell a bigger story when Virginia’s polls close at 7 p.m. ET.

Rep. Elaine Luria is fighting for her political life in the 2nd District, which leans Republican by a few points and has become a prime pickup opportunity in the GOP's quest for a majority. If she’s able to hang on, Democrats could have a good night.

In the 7th District, Rep. Abigail Spanberger is locked in an expensive race against Republican Yesli Vega. The redrawn suburban-rural district, sandwiched between Alexandria and Richmond, is a bit bluer than it was in the last few cycles, but barely. Both Democratic President Joe Biden in 2020 and GOP Gov. Glenn Youngkin in 2021 narrowly won it. If Republicans can flip this seat, they're likely to be well on their way to capturing the House majority.

And in the 10th District, Rep. Jennifer Wexton is favored to win in a suburban Washington area that includes Loudoun County and has trended from red to blue. A Republican upset here would signal serious problems for Democrats in suburbs that are central to their coalition — and a historic GOP blowout.

J. Miles Coleman, an election analyst at the University of Virginia Center for Politics, said a Luria victory would mean Democrats “could have some shot at holding the House.” If Spanberger is toppled, Republicans are on track to pick up 25 or more seats, he said; and if Wexton loses, Republicans will “likely have their biggest majority in the post-war era.”

Blue strength indicators

Polls in Ohio and North Carolina close at 7:30 p.m. ET, and if Democrats want to outperform expectations in the Senate, they’d have to start in these two open seats, which the Cook Political Report rates “lean Republican.”

In Ohio, an increasingly red state that Donald Trump carried twice by 8 points, Democratic Rep. Tim Ryan has mounted an unexpectedly strong challenge against the Trump-endorsed GOP venture capitalist and author J.D. Vance. While Vance remains favored, the matchup has forced Republican elites to spend heavily to hold the seat and made some of them queasy down the stretch. If Ryan can pull off an upset, it would be a huge boost for Democrats.

In North Carolina, a purple state where Republicans have a knack for eking out wins, the polls have shown a close race, as GOP Rep. Ted Budd maintains a narrow lead over Democrat Cheri Beasley, a former chief justice of the state Supreme Court. Democratic money groups, not writing off the race yet, have spent millions to give her a fighting chance. A victory here would mean Democrats are exceeding their marks and might hold on to the Senate.

And in Florida, where polls close at at 7 p.m. ET and others at 8 p.m. ET, Republican Sen. Marco Rubio is heavily favored to win a third term. If Democrat Val Demings is keeping it close, it would suggest a better-than-expected night for her party.

Red wave sirens

New Hampshire is one of the earliest competitive Senate contests where polls close at 8 p.m. ET, and early signs of a potential red wave would be felt in the "Live Free or Die" state.

The race pits first-term Democratic Sen. Maggie Hassan against far-right Republican Don Bolduc, a retired Army general who has promoted lies that the 2020 election was stolen. He’s a flawed candidate who Democrats wanted to face and some GOP leaders wanted to stop in the primary. Hassan has long been favored, but the race in this purple state has tightened in the final stretch. If she loses, it signifies an exceptionally strong GOP night that puts them in position to capture the Senate, given that the other key battleground Senate contests are friendly to Republicans.

The state’s light-blue 2nd District is also a potential sign of GOP strength. Democratic Rep. Annie Kuster is favored, but her victory is far from a sure thing. If she falls, it's another sign that a red wave is building.

This article was originally published on NBCNews.com