Sen. Mark Warner Joe Raedle/Getty Images After viewing classified materials as part of the Senate Intelligence Committee's investigation into Russian interference in the 2016 election, Democratic Sen. Mark Warner told The New Yorker that he came away with a conclusion: The investigation "may very well be the most important thing I do in my public life.”

The Senate committee launched its inquiry after intelligence agencies determined that Russia was involved in hacking the Democratic National Committee and Hillary Clinton's campaign in an effort to aid Trump's bid for the presidency.

Fearing the Trump administration would suppress information concerning the investigation, Warner — the ranking member on the committee — and six other of its members sent a public letter to President Barack Obama three weeks after the election requesting he declassify "additional information concerning the Russian Government and the US election."

"My increasing concern is that classification now is being used much more for political security than for national security. We wanted to get that out before a new administration took place," Sen. Ron Wyden, who also sits on the Intelligence Committee and signed on to the request for declassification, told The New Yorker. "I can’t remember seven senators joining a declassification request."

In response to concerns from Democrats that Sen. Richard Burr, the Republican chair of the Intelligence Committee, will not move the committee's investigation along quickly enough, Warner told the Washington Post that he would consider calling for the creation of an independent commission.

"If at any point we are not able to get the full information and we’re not pursuing the information to where the intelligence leads, we’ll look at other options," Warner said.

Last week, The New York Times reported that Trump campaign officials had multiple communications with senior Russian officials leading up to the election, according to intercepted phone calls. The report came just a day after Trump's national security adviser, Michael Flynn, resigned after it became clear he had discussed sanctions with the Russian ambassador before Trump took office, and misrepresented the contents of those discussions to Vice President Mike Pence.

Meanwhile, CNN recently reported that US intelligence officials have successfully corroborated conversations between Russian nationals cited in an explosive dossier containing allegations of conspiracy between Trump, his advisers, and the Russian government.

The effort to launch a congressional investigation into Trump's potential ties with Russia is becoming increasingly bipartisan. Burr said last week that he will "very likely" invite Flynn to testify before the committee. Republican Sen. Chuck Grassley and Democratic Sen. Dianne Feinstein sent a letter last week demanding the FBI provide a briefing on the circumstances surrounding Flynn's resignation and transcripts of his calls with the Russian ambassador.

Republican Sens. John McCain, Lindsey Graham, and Pat Roberts have also advocated for investigations into the administration's ties to Russia.

In an interview this week with Business Insider, Democratic Sen. Sheldon Whitehouse said that Republicans in Congress have begun to take the accusations more seriously.

"I think it's all converging to a point where people are collectively holding their breath and we will see what is the next shoe to drop," Whitehouse said. "My personal observation is that there is very little goodwill for this man with Republicans in the Senate."