Liberal activists have condemned reports that Barack Obama is considering a Republican politician to fill the contentious vacancy on the supreme court, saying such a move would be "downright absurd".

Brian Sandoval, the governor of Nevada and a former district court judge, is being vetted by the White House as a potential nominee to succeed the late Antonin Scalia, the Washington Post reported on Wednesday.

Naming Sandoval could be seen as a canny manoeuvre to call the bluff of Republicans who have vowed to neither confirm nor even hold hearings for Obama's nominee, contending that the decision should rest with the next president.

But Democracy for America, a grassroots political organisation founded by prominent Democrat Howard Dean, said Sandoval's rightwing record might oblige it to call on Senate Democrats to block his appointment.

Charles Chamberlain, executive director of Democracy for America, said: "It's downright absurd that President Obama would risk his legacy by appointing another anti-labour Republican like Governor Brian Sandoval to an already overwhelmingly pro-big business supreme court.

"Nominating Sandoval to the supreme court would not only prevent grassroots organisations like Democracy for America from supporting the president in this nomination fight, it could lead us to actively encouraging Senate Democrats to oppose his appointment."

Chamberlain added: "The American people re-elected President Obama because we wanted a leader who would ensure our courts are filled with judges who understand that our constitution is rooted in progressive values that clearly protect things like abortion rights and sit at odds with rulings like Citizens United, not country club Republicans like Brian Sandoval."

Citing two unnamed sources familiar with the process, the Washington Post reported that Sandoval, seen as a moderate Republican, is being vetted by the White House and on Monday met the Democrats' Senate minority leader Harry Reid, a fellow Nevadan. "Sandoval is increasingly viewed by some key Democrats as perhaps the only nominee President Obama could select who would be able to break a Republican blockade in the Senate," the paper added.

His nomination could leave Senate Republicans in battleground states struggling to explain why they object to one of their own. The Senate unanimously confirmed Sandoval as a district court judge in 2005 after he was nominated by President George W Bush. He quit the bench in 2009 to run for governor and has implemented Obama's Affordable Care Act. But many Democrats would find such an overtly political move unpalatable.

Former president Bill Clinton, speaking at a campaign rally for his wife Hillary in Alexandria, Virginia on Wednesday, earned enthusiastic shouts and applause when he said: "The president should make this appointment and he should appoint the best person he can find, and then if that person doesn't get a hearing, let the American people judge."

Sandoval would also come as a shock to liberal pressure groups who, despite the congressional deadlock, have been hoping for a groundbreaking nominee such as Sri Srinivasan, who would be the first Asian American on the court and has bipartisan credentials of his own.

Washington lobbyist Vincent Eng, whose clients include the National Asian Pacific American Bar Association, said he would be "surprised" if the report is accurate. "It's the president's prerogative, but I don't know if Brian Sandoval shares the values of the president. There are a lot of other candidates out there who do share the values of the president."

He warned: "There would be a lot of disappointment if Brian Sandoval is nominated, particularly because there are other options out there that are far more inspiring."

Eng also warned that, irrespective of his choice, Obama faces the big issue of a Republican-led Senate that seems determined to thwart him. "It's not an issue of who you nominate, it's the bigger principle. Whether it's Brian Sandoval or the most progressive person you can think of, it's not going to change that."

On Wednesday Josh Earnest, the White House press secretary, declined to comment on whether the administration is considering Sandoval or any other individual by name. But analysts suggested the report is credible.

Professor Verna Williams, co-director of the Center for Race, Gender and Social Justice at the University of Cincinnati College of Law, said: "My sense is that President Obama wants to do his duty. I don't think he will take the route some have suggested by nominating someone who is very far left as a way of making a point, assuring defeat and energising the Democratic base.

"The president is pragmatic and smart. That's why I'm not entirely surprised by this report. Based on what I just read, Sandoval has a lot to offer, not the least of which is the fact that he's been vetted previously for a judgeship and succeeded in getting a unanimous vote. What that means for the Democratic base, I don't know. Will they be less likely to turn out? Will they be disappointed?

"I hope not. This unprecedented show of obstructionism and disrespect for the constitution, separation of powers principles, and even democratic elections, demonstrate without question how important the next president is, which should keep people motivated to stay involved."