Sen. Lindsey Graham warned that he will subpoena the Trump administration for evidence supporting the president's claim he was wiretapped and could soon join efforts to hold up the deputy attorney general nominee.
The South Carolina Republican - one of the chief skeptics of President Donald Trump's Russia policy - added that he would block the nomination of Rod Rosenstein as the No. 2 man at the Justice Department if FBI Director James Comey does not clarify on Wednesday whether the bureau is probing the Trump team's alleged ties to Russia.
Graham made the statements on NBC's "Today" show Wednesday morning, warning that "Congress is going to flex its muscle" with the Trump administration if it does not start to provide lawmakers with answers regarding Russia.
"We'll issue a subpoena to get the information, we'll hold up the deputy attorney general's nomination until Congress is provided with information to finally clear the air as to whether or not there was ever a warrant issued against the Trump campaign," said Graham, who is leading the Senate Judiciary Committee's probe into allegations of Trump-Russia ties.
The frustration with . Comey is boiling over in the Senate Judiciary Committee, where Tuesday night, Chairman Charles Grassley, R-Iowa, said that he would not schedule Rosenstein for a confirmation vote until Comey briefed his committee on Russia. Grassley, along with ranking member Dianne Feinstein, D-Calif., first requested such a briefing after former National Security Adviser Gen. Michael Flynn resigned last month.
But preventing Rosenstein from starting his job sooner may only hurt those looking to get to the bottom of the matter. Attorney Gen. Jeff Sessions, a close Trump ally who served as a campaign adviser, has recused himself from investigating anything related to Trump - meaning it would fall to the deputy attorney general to take charge of such probes.
Grassley has given Graham, who chairs the Judiciary Committee's Crime and Terrorism panel, the reins of the full committee inquiry into allegations that Russia meddled in the 2016 elections.
Graham argued Wednesday morning that it was vital he know whether the FBI has an active criminal investigation surrounding Trump so that his probe doesn't get in the way.
"Is there an investigation? Because I need to know before I move forward into investigating Russia from a congressional lens - I don't want to interfere with a criminal investigation if there is one," Graham said. He added, however, that he thinks "the entire country needs to know if there's something there there."
Graham said he communicated to Comey the Wednesday deadline during a meeting he and Sen. Sheldon Whitehouse, D-R.I., held with the FBI director two weeks ago. Since then, he and Whitehouse have sent a formal letter to the Department of Justice, asking for any proof that wiretapping warrants were sought, or issued, against Trump and his associates. Trump charged - without offering proof - in a recent tweet that then-President Barack Obama had wiretapped his offices during the presidential campaign.
White House press secretary Sean Spicer said Tuesday that Trump is "very confident" that the president's wiretapping claim will be ultimately vindicated, though he acknowledged that Obama did not personally tap Trump's phones when he was running for president.
"I haven't heard a thing," Graham said, adding that if he doesn't receive that information today, "the Congress is going to ramp up the pressure."
In the meantime, however, Comey has been making trips to Capitol Hill to brief other lawmakers on the Senate Intelligence Committee and in the "Gang of Eight" - the lawmakers who get Congress's highest-level intelligence breifings. Comey is also scheduled to return to Capitol Hill on Monday, when he is expected to brief the House Intelligence Committee in an open hearing on issues surrounding allegations of Russian interference in the 2016 elections.
The House Intelligence Committee gave the Justice Department an extension until Monday, the day of the open hearing, to answering their letter demanding to see evidence of such wiretaps, before Chairman Devin Nunes, R-Calif., is expected to consider subpoenaing the information.
Most members of Congress who have commented on the claims say they do not believe there was ever an approved wiretap against Trump, and not a single Intelligence committee member has said they have seen any evidence suggesting the action. Though the Intelligence committees are expected to look into the allegations, any have challenged the president to back up his accusation before Congress gets too deeply involved.
"I don't think there's a warrant, but I wish they'd tell me one way or the other," Graham said Wednesday. He added this advice to the president: "If you want to challenge the Congress to do things in the future, we'll take you up on it."