Lindsey Graham wants new probe into Russia investigation to be wrapped before election

"I want to do it before the election -- I want to get all the information out there," Graham told reporters in the Capitol on Tuesday.

Graham has announced his committee plans to vote on June 4 on a broad authorization to subpoena witnesses and documents related to the FBI's Russia investigation that became former special counsel Robert Mueller's probe, and foreign surveillance warrants obtained on a Trump adviser.

Graham dismissed concerns it would look political, saying he had been "planning this for a long time."

"I'm trying to explain to the American people what happened in Crossfire Hurricane," Graham said, a reference to the FBI's codename for the Russia investigation. "I gave Mueller all the space he needed to do his job. He's done his job, we got the Mueller report, we're going to do this by October."

But Graham's timeline will fuel criticisms that his probe is part of a broader effort to use levers of government on Capitol Hill and in the Executive Branch to target the President's presumptive 2020 opponent, Vice President Joe Biden. Senate Homeland Security Chairman, Sen. Ron Johnson of Wisconsin, is also moving forward with a committee vote this week to subpoena a public affairs firm that worked with Ukrainian energy company Burisma, the firm that hired Biden's son, Hunter Biden.

And Acting Director of National Intelligence Richard Grenell this month declassified documents showing officials in the Obama administration who made authorized "unmasking" requests -- a process where officials can see the names of Americans hidden, or "masked," in foreign intelligence reports -- during the Trump transition.

Trump and his allies have used the information to attack Biden, who was included among the officials making the unmasking requests. The National Security Agency said the agency's standard procedures were followed and all of the officials had the authority to view the reports.

"In the midst of historic unemployment and economic and health tragedy, Senate Republicans are using their majority to simply block and tackle for the President's reelection campaign," Senate Minority Leader Chuck Schumer, a New York Democrat, said on the Senate floor Tuesday.

The unmasking requests are also now part of Graham's probe, and his subpoena authorization includes many officials who made the requests. Graham said the witnesses he may call will depend on the documents he receives. But he predicted he could call some of the senior officials involved in the Russia probe: former FBI Director James Comey, former acting FBI Director Andrew McCabe and former Deputy Attorney General Rod Rosenstein.

Graham said he has told Trump his panel would do a "deep dive" into the subject.

On Monday, Graham dismissed calls from Trump that he might call in former President Barack Obama to testify as part of the probe, saying he was concerned about the precedent it could set.

Graham said his investigation would be building off the Justice Department inspector general report released late last year that identified misconduct related to the Foreign Intelligence Surveillance Act warrants obtained on former Trump adviser Carter Page.

Attorney General William Barr has his own investigation ongoing into the origins of the FBI's Russia investigation. Graham said it was possible he could call Barr or someone at the Justice Department before the committee to testify on that probe.