Republican lawmakers in South Carolina have defied Donald Trump and rejected a breakneck bid to redraw the state’s congressional districts ahead of November’s US midterm elections.

In a 26-18 vote, state senators rejected mid-decade redistricting in a special session of the legislature, ending hope in Washington to split up congressman Jim Clyburn’s district and add to the list of gerrymandered gains for Republicans.

The proposal would have canceled the congressional election under way – early voting began on Tuesday morning – and rescheduled it with new district lines that would have significantly reduced the number of reliably Democratic voters in Clyburn’s district.

It comes as Republicans push to redraw voting districts to the party’s advantage in an effort to preserves its slim majority in the US House of Representatives, scrambling to leverage a recent US supreme court ruling that weakened minority protections under the federal Voting Rights Act.

The South Carolina state senate is composed of 34 Republican senators and 12 Democratic senators. Fourteen Republicans voted with Democrats blocking passage of the redistricting bill, days after a supermajority of the South Carolina state house of representatives voted to send it to the senate.

“Nineteen days ago, a map … was generated by a consultant from Washington DC, without any input from South Carolinians,” said state senator Tom Davis, a Republican from Beaufort and Jasper counties. “We were told: pass this map.”

A short-circuited process led legislators to reject the proposal, he said. The consultant who drew the map spoke with legislators via Zoom from Washington DC for seven minutes and 40 seconds before leaving without taking questions, Davis said. “Seven minutes and 40 seconds is our legislative record … I don’t know how anybody with a straight face in this chamber can vote for a map with that absence of diligence.”

Some senators said it was simply too late to make a change. “South Carolina citizens are going to the polls today. And neither my conscience or common sense is going to let me stop an election that is already under way,” Republican state senator Richard Cash said.

Clyburn, the Democrat whose district Republicans are trying to reshape in their quest for a clean sweep of South Carolina’s seven congressional seats, was among the first to cast an early ballot in the small city of Orangeburg. A defiant Clyburn insisted he would run for re-election, regardless of what the district looks like.

“I’m OK if it’s Trump plus 20,” Clyburn said while describing the potential Republican advantage in a reshaped district. “I would be running where I live.”

More than 26,000 votes were cast in South Carolina by noon on Tuesday on the first day of early voting for the 9 June primary after Democrats called for people against a proposed new map to turn out in force. In 2022, about 125,000 early votes were cast the entire two weeks.

“We’re not going to be dictated to. We’re not going to be forced to do something by Washington DC,” said Russell Ott, a Democrat from Columbia’s southern suburbs. “And I think that’s what South Carolina is all about. That’s kind of in our DNA.”

Ott said he expected some blowback toward the Republican members who rebuffed Trump’s demands. “They were put in an untenable position” by Trump, Ott said. “I think that if I’m a Republican, that’s probably who I’m pretty upset at right now. This was not something that had to happen.”

The Republican-led house already has passed a plan that would reconfigure Clyburn’s district, void the results of current congressional primaries and instead hold new US House primaries in August.

Trump has lobbied for the plan, making at least two phone calls to the Republican state senate majority leader, Shane Massey, and also phoning in to a private meeting of Republican senators earlier this month. He also has maintained the pressure on social media.

But Massey has resisted. “South Carolina has always punched above their weight,” he said during a debate earlier this month. “Doing this will diminish that influence.

“There are likely consequences for me, personally, taking the position that I am right now,” he added. I’m comfortable with that. I may not like it, but I’m comfortable with it.”

Associated Press contributed reporting