Former CBS anchorman Dan Rather said Tuesday Watergate was the biggest political scandal of his lifetime, but the current controversy over former national security adviser Michael Flynn’s pre-inauguration contacts with the Russian ambassador and the Trump campaign’s possible interactions could eclipse the bungled burglary at Democratic National Headquarters that forced Richard Nixon from the presidency.

Flynn resigned his post Monday after admitting he had misled Vice President Mike Pence about contacts with Russian Ambassador Sergey Ivanovich Kislyak, reportedly assuring him the new administration would revisit the sanctions imposed after Moscow annexed the Crimean Peninsula from Ukraine and for alleged Russian interference in the 2016 presidential election.

Flynn is the third Trump adviser to resign over Russian links. Paul Manafort resigned as Trump campaign chairman after it was revealed his name appeared in a secret ledger maintained by ousted pro-Russian Ukranian President Viktor Yanukovych, and Carter Page stepped down as Trump’s foreign policy adviser in September amid an investigation into whether he communicated privately with Russian officials.

flynn Michael Flynn (center) arrives prior to a joint news conference between Canadian Prime Minister Justin Trudeau and U.S. President Donald Trump at the White House Feb. 13, 2017, just hours before he resigned as national security adviser. Photo: Carlos Barria/Reuters

Flynn famously led chants of “Lock her up” in reference to Democratic presidential nominee Hillary Clinton during the Republican National Convention.

Democrats are demanding a full investigation.

“The American people deserve to know the full extent of Russia's financial, personal and political grip on President Trump and what that means for our national security,” House Minority Leader Nancy Pelosi said in a statement.

“By what authority did Flynn act and to whom did he report?” Pelosi asked, echoing the infamous question, “What did the president know and when did he know it” during the Watergate investigation.

Rather, in a Facebook post, said on a scale of 1-10, Watergate ranks as a nine and the Russian story currently is at a five or six.

“We may look back and see, in the end, that it is at least as big as Watergate. It may become the measure by which all future scandals are judged. It has all the necessary ingredients, and that is chilling,” Rather wrote.

The Watergate burglary itself wasn’t what forced Nixon from office in 1974. It was the subsequent coverup.

White House spokesman Sean Spicer said Tuesday President Donald Trump had been aware Flynn misled Pence for weeks. The White House counsel informed Trump immediately after the Justice Department notified him about discrepancies in Flynn’s accounts. He said Flynn resignation was a result of a breach of trust.

Pence wasn't informed until last Thursday, 11 days later, NBC reported.

Rather said the revelations now coming out about the Trump organization’s contacts with Russian officials could build the same kind of cascading pressure that made it impossible for Nixon to stay in office.

“The White House has no credibility on this issue. Their spigot of lies — can't we finally all agree to call them lies — long ago lost them any semblance of credibility,” Rather said. “I would also extend that to the Republican Congress, who has excused away the Trump administration's assertions for far too long.”

Rather called for an independent investigation.

“We deserve answers and those who are complicit in this scandal need to feel the full force of justice,” he said.