South Carolina Senator Lindsey Graham has vowed to investigate President Donald Trump's ties to Russia | Sean Rayford/Getty Images Trump in Graham’s cross hairs as Russia probe kicks off The South Carolina senator vows ‘to find out all things Russia.’

Lindsey Graham lacks the resources and access that the House and Senate Intelligence Committees have to investigate Russia’s meddling in the presidential election.

But his Senate Judiciary subcommittee has something the intelligence panels don’t: a Republican chairman viewed not as a Donald Trump ally but as a fierce critic, who has no qualms with bucking party leaders to unravel the mystery of Russia’s interference in the election.

Graham and his Democratic partner, Senator Sheldon Whitehouse of Rhode Island, will seize the spotlight Wednesday during a public hearing on Russia’s election interference, to be held by Graham’s Judiciary Subcommittee on Crime and Terrorism, which has jurisdiction over the FBI.

Graham and Whitehouse plan to use their perch to help ensure the public gets a full accounting of Russia’s intrusion and any possible ties between the Trump campaign and Moscow.

The bipartisan duo already has its first target: getting the FBI to clear up Trump’s claim that former President Barack Obama wiretapped Trump Tower in the run-up to the 2016 election. They sent a letter last week to the Justice Department asking it to turn over information that would confirm or refute Trump’s accusation — including warrant applications and court orders. The House Intelligence Committee is seeking the same information and so far neither has been unable to shake it loose.

Graham suggested Tuesday there would be consequences if the FBI continues stonewalling Congress — and said he plans to make an announcement at the start of the hearing on Wednesday warning the bureau to comply.

“If they don't honor this request and give us an answer, then I would say that we need a joint select committee because the regular order is not working,” Graham told reporters. “They’re about to screw up big time if they keep running to the Intel Committee and not answer that letter.”

Whitehouse appears more optimistic that he and Graham will get answers. In an interview with POLITICO, he said the senators got some clarity on the FBI probe after meeting with Comey privately earlier this month — the same day Attorney General Jeff Sessions announced that he was recusing from any investigations involving Russia and the 2016 presidential campaign.

“If they don't honor this request and give us an answer, then I would say that we need a joint select committee because the regular order is not working." — Senator Lindsay Graham

“We said look, we’re going to go ahead with our hearing on the 15th, just let us know by then,” Whitehouse said, recalling the March 2 meeting with Comey. “I think he implicitly confirmed that they are looking at this and he said he’d get us a clearer explanation by [the Wednesday hearing]. That was satisfactory to both of us.”

Senate Majority Leader Mitch McConnell (R-Ky.) indicated Tuesday he would not object if Graham’s panel decides to issue subpoenas to force the FBI to turn over the requested information.

“Graham is involved in an investigation of this effort, and I would not try to direct him how to do that,” McConnell said. “The core of the investigation, as you know, and we’ve said repeatedly, is being done by the Intelligence Committee. I think they will pursue whatever angles they need to pursue to get to a conclusion.”

In an interview, Whitehouse said there are key advantages to his joint investigation with Graham, more limited though it may be. For one, their subcommittee can operate in public, freed from the constraints of dealing with classified information. And the scope of their investigation is broader than it may appear at first blush, considering the FBI’s central role in federal probes looking into Russian connections.

“I do think it’s important that there be a public effort so that people can understand that Congress is in fact doing its job, and there is a forum where an investigation or information that can be discussed publicly has its day,” Whitehouse said. “We have oversight over the FBI and the FBI is all over this. So wherever they can go, we can go.”

Graham, meanwhile, said the subcommittee investigation is “going to find out all things Russia,” noting that he and Whitehouse are both former prosecutors. “I couldn’t have a better partner than Senator Whitehouse," he said.

“We’re trying to build a case,” Graham added. “So, this is what Russia's doing in other places. Then we're going to dig into what they did here.”

Graham said the probe would focus “on what laws may have been broken by the Russians and if we don't have laws to protect from this kind of stuff, we're going to need to create some.”

The South Carolina senator has emerged as one of Trump’s top GOP critics on Capitol Hill, along with his close friend, Senate Armed Services Chairman John McCain (R-Ariz.).

Running against Trump for the Republican presidential nomination, Graham called the real estate mogul a “jackass.” Since then, he has criticized Trump’s original travel ban executive order, blasted his overtures to Russia and slammed the administration’s proposed cuts to the State Department. At the same time, Graham praised Trump after having lunch with him last week and has backed Trump’s call for increased defense spending. Regardless, Graham is not up for reelection again until 2020, so he has no need to fear a primary challenge any time soon.

His willingness to buck Trump has also won him plaudits from Democrats, who view him as more independent than the chairmen of the House and Senate Intelligence Committees, Representative Devin Nunes (R-Calif.) and Senator Richard Burr (R-N.C.).

“I’m very fond of him,” Whitehouse said of Graham. “He’s a very, very talented colleague and a very good lawyer and prosecutor. He knows how legal proceedings work and is very adept.”

The intelligence panels are conducting their own wide-ranging investigations into Russia’s election meddling, and Graham acknowledged these committees have more resources and much greater access to classified information.

But the intelligence committee investigations are also viewed with suspicion by Democrats. Nunes and Burr were staunch Trump backers during the presidential campaign and agreed to White House requests last month to call reporters to rebut news reports alleging frequent contacts between Trump associates and Moscow.

"I’m more confident in Lindsey's approach," Illinois Senator Dick Durbin, the second-ranking Senate Democrat, said in an interview. "I hope that Richard Burr proves me wrong, but Senator Graham has been outspoken on many of these issues and I’ve worked with him closely so I have a lot of confidence in him."

For his part, McCain said he has a lot of trust in Graham and is glad Graham will have a role in investigating Russia’s election meddling.

“I know that these kinds of — if the word is right, scandal — these kinds of investigations always lead to more information,” McCain said. “I just think there are more questions out there that haven't been answered.”

Elana Schor contributed to this report.