Washington: Democrats in the midwestern state of Michigan have chosen Abdul El-Sayed, a left-wing Muslim doctor, to be their candidate for the US Senate in a result with seismic consequences for the midterm elections and US politics.

They rejected Haley Stevens, a four-term Democratic congresswoman heavily backed by the party establishment, despite outside groups spending more than $US60 million ($84.5 million) for her in the most expensive Democratic Senate primary ever.

His victory comes at a time when Republicans led by US President Donald Trump are painting Democrats nationwide as being overtaken by communists who want to destroy America, end capitalism and adopt a range of policies that sit outside the mainstream.

El-Sayed, who was backed by progressive hero Bernie Sanders and democratic socialist Alexandria Ocasio-Cortez, will be the Democratic candidate for a seat which the party must hold if they are to win control of the Senate in November.

The 41-year-old campaigned on a platform of taking private finance out of politics, putting money in the pockets of regular Michiganders, and universal healthcare. He promised higher taxes on the wealthy, and ending US military aid and arms sales to Israel.

The contest was tighter than many recent polls predicted, with El-Sayed winning 48.5 per cent to 47.5, or about 15,000 votes. CNN and the Associated Press called the race for him just before 10am on Wednesday (midnight AEST), when 99 per cent of the counting was complete.

Speaking at 1am local time when the votes were still being tallied, both candidates said it was time to put the bruising contest behind them come together.

“There is so much more that unites us than divides us,” El-Sayed told his supporters. “Tomorrow we begin to mend fences.”

Michigan, a swing state that voted for Trump in 2016 and 2024, last sent a Republican to the US Senate in the 1990s. But Mike Rogers, the Republican whom El-Sayed will take on in November, narrowly lost last time.

Most experts say El Sayed’s victory will make it harder for Democrats to hold the seat, while strategists were soul-searching about the party’s direction, and whether it was moving too far to the left.

Adrian Hemond, chief executive of Grassroots Midwest, a bipartisan Michigan-based public affairs group, told this masthead last week: “If he wins the primary and then loses the general election in the fall, it’s disastrous for national progressives.”

El-Sayed is the first Muslim to win the Democratic nomination for the US Senate (though not the first Republican), and would be the first Muslim to enter the US Senate if he wins in November.

Unlike Ocasio-Cortez or Zohran Mamdani in New York, he is not a member of the Democratic Socialists of America. But he has attended their events in the past, and the DSA supported his campaign. “His policy platform is socialist,” Hemond said.

El Sayed’s victory represents a heavy defeat for the Democratic elite. Stevens had endorsements from Michigan’s Democratic governor Gretchen Whitmer, multiple senators and representatives, mayors and former officeholders.

Sanders, appearing on CNN as the votes were still counted, said he couldn’t recall anything like it.

“Abdul El-Sayed is taking on the entire Michigan Democratic establishment,” Sanders said. “He’s taking on the entire national Democratic establishment. He has been outspent 10 to one.”

The $US60 million in outside funding supporting Stevens’ campaign included more than $US30 million from pro-Israel lobby groups, which became an important focus of the campaign.

Polls show the American Israel Public Affairs Committee, which funds pro-Israel candidates via super PACs, is a toxic entity among Democrats, especially younger ones - as is support for Israel more broadly.

Stevens remained a staunch supporter of the Jewish state, and once told a Hanukkah event: “Israel comes to me in my dreams.”

El-Sayed ended up comfortably winning Kent County, which takes in the city of Grand Rapids. He also easily won the state capital, Lansing, and Ann Arbor, home to the University of Michigan.

Stevens won Detroit, largely thanks to its majority population of African Americans, who are less likely to support left-wing candidates than white Democrats.

Trump weighed in on Tuesday morning claiming, without evidence, that Wayne Country - which takes in Detroit - was one of the most corrupt voting areas in the US.

“Great news for the Republican Party,” he said. “El-Sayed, a communist loser who hates Jews and Israel, is the projected winner … Now, the Dumocrats crazy policies will only get worse!”