Voters in South Carolina looked set to deliver US President Joe Biden a big win Saturday, with the first official Democratic primary of 2024 seen as a key test of support among Black voters for his reelection battle with Donald Trump.
The southern US state launched Biden on the road to the White House in 2020, and he is seeking some of the same magic four years later to build on recent momentum for a likely rematch with the hard-right Republican former president.
The 81-year-old incumbent has only two long-shot challengers in the poll which runs from 7:00 am to 7:00 pm (1200 GMT to 0000 GMT): Minnesota congressman Dean Phillips, and best-selling self-help author Marianne Williamson.
Biden has made a string of campaign visits but is staying away on Saturday, the day after US retaliatory strikes hit Iran-linked targets in Syria and Iraq following the deaths of three US troops in Jordan.
Turnout will be closely watched: Black voters drove Biden's campaign-saving 2020 South Carolina victory and then propelled him to the Oval Office, so if they stay away this time then Democrats need to worry.
A number of recent polls have shown support for Biden slipping among Black voters, especially youth, amid frustration that he has not addressed their priorities despite them backing him four years ago.
"I think the stakes are higher than it's ever been, you know people have been talking about our democracy being under attack," Biden supporter Samuel Bias, 31, said after a rally by Vice President Kamala Harris on the eve of the primary.
Biden suffers from low approval ratings, while voters have showed little appetite for a repeat of 2020's election between two men who now have a combined age of 158.
But the Democrat has gained ground in some recent polls, and in January he won an unofficial primary in New Hampshire, despite the fact that he was not on the ballot and voters had to write him in.
Biden pushed for South Carolina to be at the front of the Democratic primary this year, above New Hampshire, whose population is almost entirely white.
Despite South Carolina being likely to remain in Republican hands in November, as it has done since 1980, Biden regards it as a proving ground for his support among Black voters.
Democrats have made major campaigning efforts, with Biden visiting twice this year, including to a Charleston church where a racist gunman killed nine parishioners in 2015.
On Friday, Harris urged supporters to come out and vote in a fired-up speech at a historically Black university.
"South Carolina, you are the first primary in the nation and President Biden and I are counting on you," she told the rally in Orangeburg, South Carolina.
The first Black and woman vice president in US history, Harris also led a stinging attack on populist former president Trump, saying he had "stoked the fires of hate and bigotry and racism and xenophobia for his own power and political gain."
The results will also be closely watched to see if Biden's recent focus on attacking Trump as a threat to democracy is paying off with voters.
A New York Times/Siena poll in November found 71 percent of Black voters in six battleground states would back Biden -- down from 91 percent in the election 2020 -- and 22 percent would back Trump.
"I used to be a Democrat for 20 years. I even did the grassroots with Obama," said Regina Sidik, 56, a Black caregiver who attended a pro-Trump press conference in the state capital Columbia this week.
"But now, today after seeing what this world is going to turn out to be, I'm going Trump '24."
The Republican primary on February 24 promises to be more dramatic than the Democratic, with Trump trying to deal a knock-out blow to former South Carolina governor and UN ambassador Nikki Haley on her home turf.
