‘What did he know and when did he know it’: David Gergen asks when Trump knew about Flynn blackmail risk

Saying "This is very serious," former White House adviser David Gergen invoked the ghost of the Watergate cover-up after it was reported that President Donald Trump was warned Gen. Michael Flynn was a possible security risk subject to blackmail by the Russians.

Late Monday night, the Washington Post reported that the Trump White House had been warned that Flynn was a risk by acting Attorney General Sally Yates -- an opinion seconded by former CIA director John Brennan and former director of national intelligence James R. Clapper.

Yates was famously fired by Trump for failing to back his immigration ban on Muslims and refugees.

Discussing the bombshell report, Gergen, who wrote former President Richard Nixon's resignation letter, said the report is a major development and could impact more than Flynn.

"David," a stunned CNN host Anderson Cooper said to Gergen, "It doesn't stop. We don't have the reporting on this, it comes from the Washington Post."

"What is missing from the story so far is the president of the United States. What did he know and when did he know it," Gergen said, invoking former Sen Howard Baker's comment that opened the gates for Nixon's resignation in the face of impeachment.

"If they had a report to the legal counsel, the general counsel would have presumably reported to the president, why is Flynn still there?" Gergen continued. "It's unimaginable that the White House general counsel would sit on it, not tell anybody else in the White House. In every White House I've ever been in, this would go to the president like that," he said as he snapped his fingers.

"This is very serious stuff. If you're told that your national security adviser is potentially vulnerable to blackmail by the Russians, that is extremely serious," he concluded.

Watch the video below via CNN: