Voters in New Jersey and Virginia will choose their next governors today in a pair of races that will serve as an early gauge of the American electorate's mood after US President Donald Trump's norm-shattering nine months in office.
In New York City's mayoral race, Democratic nominee Zohran Mamdani, a 34-year-old democratic socialist, faces 67-year-old Andrew Cuomo, a Democrat running as an independent after losing to Mr Mamdani in the primary, four years after resigning as New York state's governor in disgrace.
The campaign has laid bare the Democratic Party's generational and ideological divides as it seeks to rehabilitate its damaged brand.
And in California, voters will decide whether to give Democratic politicians the power to redraw the state's congressional map, expanding a national battle over redistricting that could determine which party controls the US House of Representatives after next year's midterm elections.
Polls close first in Virginia at 7pm (midnight Irish time), followed by New Jersey, New York and California throughout the evening.
Democrats will be watching the results carefully, with the party locked out of power in Washington and struggling to find consensus on the best path out of the political wilderness.
Underscoring the stakes for Democrats, former president Barack Obama, still the party's most popular figure, headlined 11th-hour rallies over the weekend in New Jersey and Virginia, exhorting voters to elect Democrats to counter what he branded the Republican Trump's "lawlessness".
More than three million people voted early in Virginia, New York and New Jersey, in each case far exceeding the totals from four years ago. In New York City, there were 735,000 ballots cast, according to the city elections board, more than four times the number in 2021.
The New Jersey race has emerged as the most hotly contested campaign, with opinion polls showing Democrat Mikie Sherrill, a congresswoman and former navy pilot, holding a narrow lead over her Republican challenger, former state politician and small-business owner Jack Ciattarelli.
The day's other races appear less competitive. In Virginia, Abigail Spanberger, a former Democratic US representative, held a comfortable opinion polling lead over the state's Lieutenant Governor Winsome Earle-Sears, a Republican.
Voters in Stafford, Virginia, which Democrat Kamala Harris won by less than one point in last year's presidential elections, said Mr Trump's efforts to deport immigrants in the US illegally and impose costly tariffs on imports of foreign goods were top of mind.
In New York, Mamdani, who was a little-known politician in New York's state legislature only a few months ago, has led by double digits over Mr Cuomo, with Republican nominee Curtis Sliwa,71, a distant third in most opinion polls.
California's ballot measure, Proposition 50, which would install a new Democratic-backed congressional map that aims to flip five Republican seats in response to a similar move by Texas, is also widely expected to pass.
While today's results will offer some insight into the mood of American voters, the midterm elections are a year away, an eternity in politics.
"There's nothing that's going to happen in Virginia or New Jersey that's going to tell us much about what will happen in a congressional district in Missouri or a Senate race in Maine," said Douglas Heye, a Republican strategist.
For Democrats, today's candidates offer a chance to assess differing playbooks.
Ms Spanberger and Ms Sherrill, both moderate Democrats with backgrounds in national security, have put Mr Trump front-and-centre in their campaigns, seeking to harness anger at the president's no-holds-barred agenda.
Mr Trump has given each some recent grist during the government shutdown, freezing billions of dollars in funding for a badly needed rail tunnel between New Jersey and New York and threatening to fire federal workers, many of whom live in Virginia.
Mr Mamdani, running an insurgent campaign, has proposed more ambitious left-wing policies, including freezing rents for nearly a million apartments, taxing the wealthy and making the city's buses free.
Yesterday, Mr Trump endorsed Mr Cuomo, urging supporters to vote for the former governor and repeating his threat to cut federal funds to his native city if Mr Mamdani wins, although the president has no legal power to unilaterally refuse to spend funds appropriated by Congress.
Today, Mr Trump smeared Mr Mamdani, who is vying to become New York's first Muslim mayor, as a "Jew hater" that Jews should not vote for.
"Any Jewish person that votes for Zohran Mamdani, a proven and self professed JEW HATER, is a stupid person!!!" the Republican president posted on his social media platform.
Despite their ideological differences, nominees have relentlessly focused on the cost of living, an issue that has remained top of mind for voters after last year's presidential election.
"Whether it's in New York City, whether it's in Virginia, whether it's in New Jersey - frankly, throughout the country - Democratic candidates are focused on the economy, focused on affordability, focused on the issues that are really driving anxiety in this country right now," Ken Martin, the Democratic National Committee chairman, said in an interview.
For Republicans, today's elections will test whether the voters who powered Mr Trump's victory in 2024 will still show up when he is not on the ballot himself.
But Mr Ciattarelli and Ms Earle-Sears, each running in Democratic-leaning states, have faced a difficult conundrum: criticising Mr Trump risks losing his supporters, but embracing him too closely could alienate moderate and independent voters who disapprove of his policies.
Mr Trump remains unpopular: 57% of Americans disapprove of his job performance, a Reuters/Ipsos poll shows. But Democrats are not gaining support as a result, with respondents evenly split on whether they would favour Democrats or Republicans in 2026.
