US midterms: When will we know who controls Congress?

The short answer to the million-dollar question is this: how long it takes to know the results of Tuesday’s midterm elections will depend on how close the races are. If the polls are broadly correct, control of the House of Representatives could be decided by tonight, while the Senate may become clear in the early hours of Wednesday morning. But if the key contests are tight, it could take days, or even weeks, to determine the Senate’s balance of power. The House could also take longer than expected.What to expectDemocrats need 218 of the House’s 435 seats to win control. At the end of October, forecasting models from Silver Bulletin and The Economist gave them a 95% chance of doing so, while Decision Desk HQ put their odds at 80%.The Senate is a closer contest. Republicans currently hold 53 seats and need only 50 to retain control, since Vice President J. D. Vance can cast the tie-breaking vote. Democrats need 51 seats, meaning they must gain four more seats than they lose.According to EL PAÍS’s polling average, Democrats are leading in North Carolina, Ohio, Maine, Texas, Kansas, Alaska and Iowa, all currently represented by Republican senators. But the margins are narrow: about three points in Kansas, Ohio, Texas and Maine; roughly one point in Alaska; and less than half a point in Iowa. Those leads are well within the typical margin of error of political polling.What to watch, hour by hourAll times are Eastern Time. The first results will begin to come in as soon as polls close. 7:00 p.m.: Georgia and Virginia. The first competitive House districts to report are in Virginia. In Georgia, Democrat Jon Ossoff is defending his Senate seat with a polling lead of about nine points. If that race looks competitive, it would be an ominous sign for Democrats.7:30 p.m.: North Carolina and Ohio. This is the first real test for the Senate. In North Carolina, Roy Cooper leads Michael Whatley by roughly 11 points. In Ohio, Sherrod Brown holds a three-point advantage over Jon Husted. If Brown wins, the Democrats’ path becomes much easier; if he loses, they will need to win almost everywhere else.8:00 p.m.: Pennsylvania, Florida, New Jersey, Maine and New Hampshire. Many of the most competitive House districts are located in these states. In Maine, Susan Collins trails Troy Jackson by about three points, but the state uses ranked-choice voting. If no candidate wins more than 50% of first-preference votes, it could take days before a winner is known.9:00 p.m.: The crucial hour for the Senate. Polls close in Texas (where James Talarico faces Ken Paxton), Iowa, Kansas, Michigan, Minnesota and Nebraska, where independent candidate Dan Osborn trails Republican Pete Ricketts by less than two points. Key House districts in New York, Wisconsin, Arizona and Colorado will also be reporting results.11:00 p.m.: California, Washington and Oregon. California counts votes slowly. If control of the House remains in doubt by then, districts in the state could delay a final outcome for several days.1:00 a.m.: Alaska, where Mary Peltola and Dan Sullivan are running nearly neck and neck. Alaska typically takes about two weeks to complete its vote count.Three possible scenariosDemocrats take control early: If Roy Cooper and Sherrod Brown win early the Senate races in North Carolina and Ohio, and James Talarico and Josh Turek prevail in Texas and Iowa, Democrats would secure the four seats they need by the early hours of the morning, without having to wait for Maine or Alaska. That is assuming they hold on to all the Democratic-held seats currently up for election. The House would likely be decided even earlier, much as it was in 2018, when Democratic control became clear on election night.A nail-biter: If control of the Senate comes down to Maine and Alaska, there is little chance of a result tonight. In 2022, the Senate was not decided until the following Saturday, while the House remained unresolved for another eight days after Election Day.Republicans hold on: If Jon Husted keeps Ohio in Republican hands and Susan Collins survives in Maine, Democrats would need to win virtually all of the remaining competitive races. In that scenario, Republicans could effectively secure control of the Senate in the early hours of the morning, once results from Texas and Iowa are called. It is worth being cautious with the first wave of results. States count early votes, Election Day ballots and mail-in votes in different ways and in different orders. That can create an early advantage for one party that later fades as more votes are counted.Sign up for our weekly newsletter to get more English-language news coverage from EL PAÍS USA Edition