WASHINGTON, DC - SEPTEMBER 02: U.S. President Donald Trump leaves the podium after speaking as he hosts a dinner in the Rose Garden at the White House on September 02, 2026 in Washington, DC. President Trump invited Republicans in competitive races to a Rose Garden dinner ahead of the November elections. Kevin Dietsch/Getty Images/AFP
Voting in the US midterm elections effectively began Friday as North Carolina became the first state to send out mail ballots for contests expected to threaten President Donald Trump's Republican control of Congress.
The November 3 elections will decide all 435 seats in the House of Representatives and a third of the Senate, determining how much freedom Trump has to pursue his agenda during the remaining two years of his term.
Democrats enter the final months favored to take the House.
A new Cornell University forecasting model gives them an eight-in-10 chance of winning control and projects a roughly 226-209 majority, while other forecasters similarly give the opposition party an edge.
The Senate is expected to be much closer. Republicans hold a 53-47 majority, leaving Democrats needing a net gain of four seats, while Decision Desk HQ has projected a possible 50-50 chamber in which Republican Vice President JD Vance would cast tie-breaking votes.
"These forecasts aren't deterministic -- there is uncertainty," said Peter K. Enns, professor of government and policy at Cornell.
"But given our model's impressive historical accuracy, if Republicans hold the House, it likely means either everything has gone their way or something unprecedented has happened."
Trump himself will not appear on the ballot, but Republicans are portraying the election as a referendum on his presidency and urging supporters who backed him in 2024 to turn out again.
The president's party faces traditional midterm headwinds alongside low approval ratings, voter concern over prices and the war with Iran.
Voting begins amid turmoil over mail ballots.
Trump is asking the Supreme Court to allow the Postal Service to impose new verification requirements that have been temporarily blocked by a federal judge, while an agency whistleblower has warned that the hastily developed system could disrupt delivery of ballots.
North Carolina officials said their mail voting would nevertheless proceed as planned.
Other states begin distributing absentee ballots throughout September, with all required to send ballots to military and overseas voters by the middle of the month.
