Election eve: Polls point to Democratic gains as US confirms limited Iran strikes

Polls opened at 7am on the US East Coast on Tuesday, 11pm AEDT, in midterm elections that will shape the second half of Donald Trump's presidency. Early polling strongly suggests the Republicans are about to lose the House, and perhaps the Senate as well, to the Democrats.

The day's schedule is staggered. Polls begin closing at 6pm Eastern, which is 10am Wednesday AEDT. Texas and most Midwest states close at 9pm Eastern, and Alaska at midnight Eastern. All 435 House seats are up, along with 35 of the 100 Senate seats. The result will decide whether the Democrats can blunt Trump's agenda or whether he keeps his grip on Washington until the next presidential election in November 2028.

The arithmetic is tight. Control of the House takes 218 seats, which is exactly what the Republicans hold now. The Democrats hold 214, two seats are vacant after resignations, and one belongs to Californian Kevin Kiley, who was elected as a Republican but became an independent in March. The Democrats need a net gain of four. In the Senate, Republicans hold 53 seats and Democrats 45, with independents Bernie Sanders and Angus King caucusing with them. The Democrats need 51 for control. A 50-50 split would leave the deciding vote with Vice President JD Vance, and so with the Republicans. The 35 contests include special elections for the Ohio and Florida seats vacated by Vance and Marco Rubio, both since filled by temporary appointments.

Trump closed the Republican campaign with a speech at the Lincoln Memorial Reflecting Pool in Washington, the site of a botched renovation. He dwelt on his remaking of the capital and did not mention the election for the first 20 minutes. He noted the latest fall in oil prices and promised energy costs would come down "a lot further" once the war against Iran ended. The overnight Reuters/Ipsos poll put his approval rating near a record low, though it hinted the congressional contest might be tightening. Other polling pointed to a blue wave in both houses.

Hours later, US officials told the Wall Street Journal that the military had carried out limited strikes on Iranian targets in the Strait of Hormuz. Iran's state-run Islamic Republic News Agency reported five blasts in quick succession on Qeshm Island, and said residents had seen planes overhead. An anonymous American official described the strikes as defensive, aimed at Iranians firing surface-to-air missiles at US assets. They appeared limited rather than a return to full hostilities. Trump had earlier said the US would not strike Iran before the elections, and the unpopular war, with its effect on petrol prices and the wider economy, has been a vulnerability for Republicans. Vance told reporters that he and Trump felt "pretty good" about the prospects of a negotiated settlement. Australian Treasurer Jim Chalmers said the result could carry big economic consequences for Australia, particularly for the Middle East war, noting that Americans have a say in when it ends and Australians do not.

Two Senate races stand out. In Alaska, Republican Dan Sullivan used an election-eve address to attack Democrat Mary Peltola over an alleged effort to put a candidate with his own name, Dan Sullivan Jnr, a retired teacher, on the ballot. The allegations come from the New York Times. Sullivan stopped short of accusing Peltola of illegal conduct but said he had met a handful of people who voted for the wrong Dan Sullivan. Peltola denies involvement, and Sullivan Jnr denies coordinating with her campaign. In Texas, Republican Ken Paxton faces Democrat James Talarico, a seminarian and former school teacher. Elon Musk has put in $677 million this cycle, according to the Times, behind only Michael Bloomberg's 2020 spending. About $300 million went to his own super PAC and $240 million to a Senate leadership fund backing Paxton. The records run only to mid-October.

The day also carried legal and civic tensions. The Supreme Court rejected a push for California to set aside thousands of mail-in ballots from people the Trump administration claims are non-citizens. Attorney-General Todd Blanche encouraged people to report suspected non-citizen voters, prompting fears of unrest or vigilantism at polling places. Trump still falsely claims he won in 2020 and has cast doubt on the integrity of these midterms. His administration has pressed states for voter data and opened non-citizen voting investigations that experts say have found little evidence. Observers also warn of "mirages", where early counts favour one party before shifting, which is a product of reporting order rather than evidence of tampering.

What to watch is how Trump responds if Republicans lose one or both chambers, and whether Texas and Alaska decide the Senate.