US president Donald Trump devoted his final public remarks before Tuesday’s midterm elections to touting renovations of the Lincoln Memorial Reflecting Pool, even as Democrats sought to contain ‌a rift in Michigan’s closely fought US Senate race.

Over a fast-moving weekend, US representative Haley Stevens, who lost the Michigan Democratic Senate primary to Abdul El-Sayed in a bitter contest, suddenly switched to backing Republican Mike Rogers ​and appeared with him at a Detroit church. The race is critical to Democrats’ hopes of ending the 53-47 Senate majority hold of Trump’s Republicans in Tuesday’s vote.

In his only public remarks scheduled for Monday, Trump, a former real-estate developer, spent more than 20 minutes discussing pipes, joints, caulking, granite resurfacing, algae and leaks at the belated reopening of the Washington reflecting pool.

He made brief reference to the election, saying: “When you vote, ⁠remember: a party that hates America cannot be allowed to rule over the people who built our country.”

Non-partisan analysts generally favour Democrats’ chances of winning a majority in the House of ‌Representatives. ‌Control ​of the Senate is more uncertain, with analysts seeing traditionally Republican-leaning states including Texas, Kansas and Iowa as competitive and giving Democrats more possible paths to a majority.

A worker prepares mail-vote ballots for scanning in Orange County, California last week. Photograph: Apu Gomes/Getty ImagesA worker prepares mail-vote ballots for scanning in Orange County, California last week. Photograph: Apu Gomes/Getty Images

Control of either chamber would constrain Trump’s ability to pass legislation and empower Democrats to investigate his administration, while a Senate majority would also allow them to block his appointees ⁠to federal courts including the US supreme court.

The Trump administration has sought ​to intervene in election disputes in Alaska and California. A federal judge on Sunday dismissed a US justice ​department lawsuit seeking to block certification of election results in Alaska if Republican incumbent senator Dan S Sullivan narrowly loses.

The supreme court also quickly rejected on Monday a bid by the administration to temporarily block California from counting mail-in ballots from more than 20,000 registered voters who federal officials allege are likely non-US citizens.

The court denied the US justice department’s emergency request, shutting down the claims over disputed ballots that could have affected thousands of voters and injected uncertainty into election outcomes.

[ US midterm election night: When Irish viewers can expect the key callsOpens in new window ]

In Michigan, after Stevens’s endorsement of Rogers, El-Sayed’s campaign said ⁠it raised $2.4 million (€2.14 million) on Sunday, its largest single-day fundraising haul, fuelled by small-dollar donations averaging $36.74 ⁠from more than 65,000 donors.

El-Sayed, an Egyptian-American Muslim ​born in Michigan, has been targeted by Trump and other Republicans who have repeatedly questioned his loyalty to the US and baselessly called him a terrorist sympathiser whose election would invite attacks on Americans. El-Sayed has called questions about his loyalty to the US “shameful.”

The verbal attacks fit a broader pattern of inflammatory rhetoric from some Republicans targeting Arab Americans, Muslims and transgender people and portraying Democrats as communists and dangerous radicals ahead of the midterms.

In Alaska, the US justice department argued voters may be confused by the presence of a challenger named Daniel J Sullivan jnr on the same ballot.

[ Race narrows between a ‘radical Democrat’ and ‘the most corrupt politician in Texas’Opens in new window ]

The issue has roiled the campaign over the last ​several days after The New York Times reported that Democrat Mary Peltola’s campaign was involved in recruiting the latter Sullivan into the race as a ​spoiler.

The senator said on Sunday he would accept the results of Tuesday’s election even as the Trump administration presses a criminal investigation into the issue.

Peltola has denied involvement, and Sullivan jnr has denied co-ordinating with Peltola’s campaign. – Reuters

How we’re covering the US midterms

Midterms

Follow Irish Times Washington Correspondent Keith Duggan and video journalist Chris Maddaloni in the final week of the campaign as they report from key battlegrounds and gauge the mood of voters across the US.

More US midterm election coverage here.