As Special Counsel Robert Mueller’s probe hits the one-year mark Thursday, Republicans in midterm elections have started to see an opportunity to use the Trump controversy to their advantage – by appealing to voters tired of the never-ending investigation.

Candidates in some GOP primaries this year already have worked to woo Trump supporters by arguing it’s time to end the Russia probe. Other Republicans are likely to follow suit amid a sense of Mueller investigation fatigue.

“I think you could see others embrace that messaging because the states that are up in 2018 on the Senate side are super red,” one Republican strategist involved in the midterms told Fox News.

Whether the message has appeal beyond a Republican primary audience remains to be seen, but it could serve to motivate the GOP faithful to the polls and increase turnout.

The strategist added: “I think Trump voters don’t think Mueller has anything, so that messaging could be impactful to rile up folks that sat out until 2016 to vote for Trump.”

Republicans, like Rudy Giuliani, a member of the Trump’s legal team, have predicted the Mueller probe could energize Trump supporters in November.

“It has his people much more excited now than before,” Giuliani recently told Politico.

DEMOCRATIC CONGRESSMAN PUSHES TO IMPEACH TRUMP

But not all Republicans think it’s a worthwhile strategy in the general election, as the cloud from the Mueller probe could continue to harm the party down the ballot.

“I think the Republican posturing toward Bob Mueller in primaries became sort of a litmus test as to who was the most pro-Trump candidate,” Colin Reed, a Republican strategist and veteran of statewide campaigns in past cycles, told Fox News. “I think as the primaries start to fade into the rear view mirror, it’s going to be less and less of an issue.”

Reed said Republicans are the “law and order party,” and therefore should support giving Mueller room to complete the investigation.

“We should support guys like Robert Mueller,” Reed said. “And we shouldn’t be the ones launching attacks on him. He’s someone who was nominated by George W. Bush, confirmed overwhelmingly and commands universal support from both parties.”

In recent weeks, Republicans in competitive primaries have been calling for an end to the probe.

In Montana, GOP Senate candidate Troy Downing tweeted: “#Mueller investigation going on too long, no collusion, needs to end! #mtpol #mtsen”

In Indiana, Rep. Todd Rokita mentioned Mueller in an ad and said: “Who’s tough enough to stop the witch hunt?”

Rokita, who lost the primary to Republican businessman Mike Braun, also introduced a House resolution during the campaign demanding the Mueller investigation produce evidence of collusion, or end the investigation within 30 days.

During a debate in last month’s GOP primary in West Virginia, all three Republican candidates blasted the special counsel investigation into the Trump administration’s ties with Russia.

“With respect to the Mueller investigation, I think it needs to come to an end,” state Attorney General Patrick Morrisey, who went on to win the primary, said. “It's a witch hunt. We need to stop that.”

His primary opponent, Rep. Evan Jenkins, during the debate, flatly said: “End this investigation now.”

In Mississippi, Republican Senate candidate Chris McDaniel has also taken aim at the length of Mueller’s investigation.

“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 told the Washington Post.

Democrats are also trying to use the Russia probe to bolster their chances, seizing on the indictments and daily news stories to try to inflict damage on Republicans. Some Democrats, citing the Russia probe, also have backed impeachment efforts against Trump.

The president, who has called the Russia investigation “phony,” has used the impeachment talk to rile up supporters at rallies, drawing attention to comments made by California Democratic Rep. Maxine Waters.

“We have to keep the House because if we listen to Maxine Waters, she’s going around saying ‘We will impeach him,’ ” Trump said last month.