Republican Senate candidates in competitive primary races have begun to call for an end to the special counsel’s investigation of Russian tampering in the 2016 election, breaking from congressional GOP leaders.

Candidates in Montana, Indiana, Arizona and Mississippi have gone public since Sunday with their concerns that the investigation by Robert S. Mueller III has gone on too long, expanded too broadly or is motivated by improper partisan interests.

All are competing in states President Trump won easily in the 2016 campaign.

The comments come as many candidates scramble to win over Republican primary voters by attempting to appear more supportive of Trump’s presidency than their rivals.

The Republican Senate candidates are echoing concerns voiced by Trump, who last week called the investigation a “total witch hunt,” “an attack on our country” and “a disgrace,” while charging that Mueller’s team is “the most biased group of people.”

The comments run counter to the views of House Speaker Paul D. Ryan (R-Wis.) and Senate Majority Leader Mitch McConnell (R-Ky.), who have called for Mueller to be left alone to do his job.

“I don’t think he should fire Mueller, and I don’t think he’s going to,” McConnell said Tuesday in an interview with Fox News, in saying why he would not allow a vote on a bill to limit Trump’s ability to obstruct the Mueller probe.

“This has gone too far. Something has to be done,” said former Maricopa County sheriff Joe Arpaio. Arpaio is running for Senate in Arizona with a campaign centered on his support for Trump, who pardoned him in August for criminal contempt of court. “Whatever action he takes, I’ll back him up, whether he fires these guys or not.”

Troy Downing, a GOP candidate in Montana, took to Twitter on Monday to express his displeasure, with syntax that echoed the president.

“#Mueller investigation going on too long, no collusion, needs to end!” the tweet said.

All three Republican Senate candidates in Indiana said Sunday at a debate sponsored by WISH-TV in Indianapolis that the Mueller inquiry should end, though they stopped short of calling on Trump to fire Justice Department officials to stop the probe. “Hoosiers want us to get past this Russian issue,” Rep. Luke Messer (R-Ind.) said. “It’s outrageous. It needs to end.”

The other two candidates, businessman Mike Braun and Rep. Todd Rokita (R-Ind.), also claimed Mueller’s team was politically biased. “He’s not a trusted source. He’s not going to be a neutral umpire,” said Rokita, who has gone after his opponents on the grounds they are not sufficiently supportive of the president. “That probe should end because it has found nothing.”

Mueller’s team has so far brought indictments or secured guilty pleas against 19 people, including Trump’s former campaign chairman Paul Manafort, former national security adviser Michael Flynn, former deputy campaign chairman Rick Gates and 13 Russian nationals.

Last week, FBI agents raided the offices of Trump’s personal attorney and longtime adviser Michael Cohen as part of an investigation referred to federal prosecutors in New York from Mueller’s team.

While the candidates have criticized the Mueller investigation, they have offered few specifics on how it should end.

In Mississippi, state Sen. Chris McDaniel said the probe should be “expedited,” though he stopped short of calling on Trump to try to fire anyone to short-circuit the probe.

McDaniel, who has been hostile to Senate GOP leaders, is running for the seat currently held by Cindy Hyde-Smith (R), who replaced Republican Thad Cochran when he stepped down amid health problems.

“We need to find ways to put, if possible, deadlines on the investigation itself. So, put simply, we don’t want a person on a witch hunt indefinitely,” McDaniel said. “It’s in the best interest of the Trump presidency to allow the investigation to conclude.”

A clear majority of Americans support Mueller’s probe, according to a recent poll by The Washington Post and ABC News.

This includes nearly 7 in 10 who support Mueller’s focus on possible collusion with Russia, 64 percent who say they want him to investigate Trump’s business activities and 58 percent who want him to investigate alleged payments by associates to silence women who say they had affairs with the president before he took office.

The same poll found a majority of Republicans, who make up about 1 in 4 poll respondents, oppose the Mueller investigation. Just 43 percent of Republicans supported Mueller’s collusion investigation, 34 percent supported the investigation of Trump’s business activities, and 29 percent supported the investigation of potential hush money to women.

Senate candidates who do not face serious primary challenges have tended to take a different approach to questions about the Mueller investigation in recent weeks.

“I wouldn’t dismiss him,” said Florida Gov. Rick Scott (R) over the weekend of Mueller. Asked whether he would support a Senate bill to make it more difficult for the president to end the special counsel investigation, Scott did not give a direct answer.

“It needs to be complete transparency,” he said of the investigation. “And we need to make sure, whatever investigation it is, the facts get out there.”

Republican Sen. Dean Heller, who is running for reelection in Nevada, told reporters in a conference call last week that he does not want the president to fire Mueller, though he hopes the probe wraps up soon. “I hope he [Trump] doesn’t do it,” Heller said, according to a report in the Pahrump Valley Times.

In a Monday telephone interview with The Post, North Dakota Senate candidate Rep. Kevin Cramer (R), who is running against Sen. Heidi Heitkamp (D), said he feels “some of the president’s frustration” with the investigation. Cramer, a close Trump ally, did not embrace one of the labels Trump has used to disparage the Mueller probe.

“I don’t get the sense he’s on a witch hunt, per se. In fact, if anything, I get the sense that maybe he is starting to see an end to some of this,” Cramer said. While Mueller is “trying to stay in the lane,” Cramer said, he has grown frustrated with the “mission creep” of the special counsel and “the lack of accountability.”