Shepard Smith asked Sen. Mark Warner (D-VA) this afternoon whether Congress could demand that President Donald Trump release his tax returns.

"Do you think that might be illuminating on any potential dealings with Russia?" Smith asked.

Warner, vice chairman of the Senate Select Committee on Intelligence, said the committee would have "subpoena power" in an investigation, but it's an "open question" on whether they would seek the tax return documents.

"There are a number of members of both parties that wish that Mr. Trump would have followed historical precedence that was set by every presidential candidate, Democrat or Republican, and released that [information]," Warner answered.

Warner said he expects the intelligence committee to be briefed by officials on the contents of the phone calls between former national security adviser Michael Flynn and the Russian ambassador. 

"We need to see the contents of that conversation before we leap to some conclusion," said Warner. 

Smith asked why there have been no indictments stemming from the year-long FBI investigation and why viewers shouldn't see this as a "political smear campaign."

Warner said he and committee chairman Richard Burr (R-NC) want to move forward in an "orderly fashion" and in a bipartisan way. He said some people want to "sweep this under the rug" while others want to "turn this into a witch hunt."

Earlier today, Sen. Ben Cardin (D-MD) called for an independent commission to be formed - similar to the 9/11 Commission - to investigate Russia's interference in the election.

Cardin, the ranking member on the Senate Foreign Relations Committee, likened the current situation to the period after the 9/11 attacks, arguing that American national security could be vulnerable.

On the other side, Rep. Trey Gowdy (R-SC) said the House Intelligence Committee has been investigating Russian meddling in the election "for months" and criticized Democrats for being more interested in politics than facts. 

It came after reports last night of extensive communication between the Trump campaign and Russian intelligence officials in the year before the election.

Watch the full interview above.

Dan Rather: Trump's 'Russia Scandal' Could Be Bigger Than Watergate

'Wake Up!': Kucinich Says Intel Community Making 'Unprecedented' Effort to Upend Trump

Trump: New Reports on Russia Connections Are 'Conspiracy Theories'