NEW YORK (AFP) - The midterms are coming - and celebrities, business leaders and even smartphone apps are pitching in to get as many Americans as possible to the polls for a key test of Mr Donald Trump's presidency.
On Thursday (Nov 1), television icon Oprah Winfrey was the latest star to come out for the Democrats, campaigning door-to-door for Georgia gubernatorial candidate Stacey Abrams in an Atlanta suburb.
That followed the release of an ad produced by former New York mayor Michael Bloomberg and featuring actresses including Julianne Moore, Jodie Foster, Ellen Pompeo and the singer Cher.
Meanwhile, businesses from clothing giants Gap and Levi's to Walmart as well as the ride-sharing apps Lyft and Uber are taking steps aimed at boosting turnout.
Some will give their employees the day off to vote, while Lyft and Uber will offer cut-price rides to polling stations.
Music streaming platforms Spotify and Pandora are targeting young people, whose participation is historically particularly feeble, with playlists featuring direct links to voter registration resources.
Elsewhere, dating app Tinder is sending its users voting reminders, a measure introduced during the 2016 presidential election.
All these appeals do not specifically mention Mr Trump, or any candidate - but they are more likely to mobilise potential Democrats, said Harvard University political science professor Thomas Patterson.
While Republican voters are more "stable", he said, Democrat-leaning minorities and young people generally "are more responsive to the circumstances of the moment."
TRUMP VERSUS ANTI-TRUMP
Midterms traditionally see low voter turnout: in 2014, national participation stalled at just 37 per cent, a record low since World War II.
But this year, Dr Patterson and other experts believe sharp political divisions will spark a rise, with the latest polls predicting higher participation in 18 states and the capital Washington.
Figures compiled on Saturday by Dr Michael McDonald of the US Elections Project show that at least 34 million Americans voted early - either by mail or in person - far higher than the 27 million of 2014.
Dr Patterson is among those who expect total participation on Tuesday to surpass 40 per cent. Others suggest turnout could exceed even 50 per cent - a level not seen since the start of the 20th century.
The midterms are usually decided on local issues, but this year is different.
"The midterms have become a fully national election," Dr Patterson said.
"It's the Trump versus the anti-Trump forces."
And both ends of the spectrum could be mobilised by recent events, he added.
Most recently, a series of mail bombs sent to top Democrats by a Trump supporter and a mass shooting at a Pittsburgh synagogue could stir apathetic Democrats.
On the other hand, a Central American migrant caravan heading to the US-Mexico border could spur Republicans, already riled up by the battle to confirm Supreme Court Justice Brett Kavanaugh after sexual assault allegations surfaced.
However, the impact of such events is tough to predict and often fleeting.
While February's Parkland school shooting in Florida could have boosted youth turnout in the immediate aftermath, "a lot of that energy got dissipated over the summer," Dr Patterson said.