Sen. Richard Blumenthal (D-Conn.) said there is a "looming constitutional crisis" a day after the firing of FBI Director James Comey.
"What we have now is really a looming constitutional crisis that is deadly serious," Blumenthal told CNN's "New Day" on Wednesday.
"Because there is an investigation, ongoing, and CNN reported subpoenas issued from the eastern district of Virginia into Flynn associates and ultimately, there may be subpoenas to the president of the United States."
Blumenthal compared the current situation to the Watergate scandal.
"Just as occurred in 1973, precipitating United States v. Nixon and a similar firing of a special prosecutor," he said.
"So what's needed now is in fact an independent counsel and special prosecutor."
President Trump on Tuesday fired Comey, who had been leading the investigation into ties between the Trump campaign and Russia.
The move sent the political world into a frenzy, sparking outrage from Democrats, who said Trump was attempting to shut down the FBI’s investigation.