Biden will appear in Westchester County on Sunday, normally safe Democratic territory, where Republicans are nonetheless threatening to make gains, thanks in part to relentless messaging painting their opponents as soft on crime and inflation.

New York’s Democratic Governor Kathy Hochul is facing an unexpectedly stiff challenge from Republican Lee Zeldin, while Democratic incumbents in the US House of Representatives are locked in tight battles throughout the state.

Trump, meanwhile, will appear in Miami on Sunday alongside both the state’s US senators and several US representatives.

Florida for years swung from party to party, but has recently trended Republican and is not considered a major battleground this election.

Trump’s frequent rallies have served to maintain his own profile as he contemplates launching a third run for the White House after the midterms, according to advisers.

Florida, in particular, could serve as an important battleground in any nominating contest, as its Republican governor, Ron DeSantis, is viewed by strategists as a formidable contender for the Republican nomination, should he throw his hat in the ring.

That has made DeSantis an increasingly frequent target of Trump, who referred to the governor as “Ron DeSanctimonious” at a Saturday evening event.

Key Democratic and Republican figures have been campaigning heavily in recent weeks. Both Trump and Biden appeared in Pennsylvania on Saturday, as did former Democratic president Barack Obama.

First lady Jill Biden will attend get-out-the-vote events for Harris County Judge Lina Hidalgo in Texas on Sunday, while Vice President Kamala Harris will be in Chicago, whose suburbs host a pair of competitive House races.

For Democrats, the Sunday rallies – held in areas that are traditionally friendly to the party – are a last-minute opportunity to minimise losses on Tuesday.

In recent weeks, the momentum has shifted toward the Republicans, Democratic strategists acknowledge, as voters’ concerns about inflation and crime have proven more durable than concerns about abortion.

Democrats’ early lead in several Senate races, including contests in Pennsylvania, Georgia and Nevada, have shrunk or evaporated completely in recent weeks.

Top Democrats have emphasised their work to lower prescription drug prices and portrayed their opponents as a threat to social security in recent rallies, while Republicans have questioned the firmness of their opponents’ support for law enforcement and criticised their handling of the US-Mexico border.

Nonpartisan election forecasts and polls show Republicans are heavy favourites to win control of the House of Representatives, with the Senate a toss-up.

Control of even one of those chambers would give Republicans the power to block Biden’s legislative agenda and launch potentially damaging investigations.

Also playing against the Democrats is Biden’s unpopularity. Only 40 per cent of Americans approve of the president’s job performance, according to a Reuters/Ipsos poll completed on Tuesday, which has led Biden to hold back from campaigning in some swinging states.