Last week Sen. Jeff Merkley was asked what keeps him up at night. The question came just a few days after President Donald Trump fired James Comey as FBI director.

“We’re staring into the abyss,” Merkley told Willamette Week during a May 12 interview. “We’re on the edge of a constitutional crisis.”

Since then, we’ve seen another week of bombshell reports about Trump. The New York Times reported that Trump asked Comey to stop his investigation into Michael Flynn during a February meeting. The Washington Post also reported that Trump divulged highly classified information to the Russian foreign minister during an Oval Office meeting.

“I think we are plunging into the abyss,” Merkley told KGW on Wednesday, updating his previous assessment of the president. Watch the interview

Merkley has joined bipartisan calls for the FBI to turn over memos reportedly written by Comey that detail his meetings with Trump.

“When you have this kind of information about the potential obstruction of justice in America you have to get to the bottom of it,” Merkley said. “We have to get to the bottom of whether the Trump campaign conspired with the Russians to destroy the integrity of America’s presidential election.”

Merkley said it would be a “very big deal” if the memos show that Trump directly asked Comey to stop an investigation into Flynn and Russian election meddling.

“If you tell an FBI director to stop an investigation and you fire them because they don’t stop the investigation that sounds very much like obstruction of justice,” Merkley said.

He stopped short of calling for Trump to be impeached, but said it could come to that eventually.

“Quite frankly the standard for obstruction of justice may be different than the standards for high crimes and misdemeanors. There may be conduct here that is appropriate to take on hearings in the House based on what’s we learn. Let’s get the facts,” Merkley said.

The Constitution gives the House of Representatives the power to impeach a president. The Senate would only decide an impeachment trial after the House voted to impeach a president.

Merkley said he’ll attend a a closed-door briefing in the Senate on Thursday with Deputy Attorney General Rod Rosenstein.

Rosenstein wrote the memo that Trump originally used to justify Comey’s firing before admitting in an NBC News interview he previously intended to fire him.

“What I want to know is was he asked to create a cover story or what he involved in misleading the American people?” Merkley said.