Last week’s admission by Michael Cohen that he lied to Congress about a Trump Organization real estate project in Moscow suggests the Russian government may have damaging information about President Trump, a top Democrat said Sunday.

Rep. Jerrold Nadler (D-N.Y.), the incoming chairman of the House Judiciary Committee, said in an appearance on NBC’ News’s “Meet the Press” that Thursday’s guilty plea by Cohen, Trump’s former personal attorney, raises the question of whether Russia continues to have leverage over Trump.

“Does the Kremlin have a hold on him over other things?” Nadler said. “There certainly was leverage during the campaign period and until recently because they knew he was lying, they knew he had major business dealings or that Cohen on his behalf had major business dealings.”

Nadler also said lawmakers “must do whatever we can” to protect special counsel Robert S. Mueller III’s Russia investigation from interference by Trump.

“We have a president who lies incessantly to the American people about big matters and small matters. . . . The time when he can get away with lying to the American people all the time and evading accountability is coming to an end,” Nadler said.

Sen. Benjamin L. Cardin (D-Md.) also defended the Mueller probe on “Fox News Sunday.” Trump has repeatedly decried the investigation as a “witch hunt.”

“I think that America, which stands for the rule of law, the leading democratic country in the world, our president needs to respect the independence of this investigation,” Cardin said.

Cohen last week pleaded guilty to lying to Congress about a Moscow real estate project that Trump and his company pursued at the same time that he was securing the GOP nomination in 2016. Cohen told prosecutors that he had lied to distance Trump from the project during the hotly contested presidential race.

Sen. Mark R. Warner (D-Va.) said Sunday that “most Republicans who were about to nominate Donald Trump in the summer of ’16 would probably have thought it was a relevant fact” that Trump was still trying to do business with Russia at the time.

He added, in the wake of Cohen’s guilty plea, it has become clear that “most of these characters who are around Donald Trump, none of them have exactly a sterling record of telling the truth.”

“What I find particularly interesting with the revelation of Cohen’s plea is that he’s saying he lied to protect then-candidate Trump’s stories that he had nothing to do with Russia,” Warner said on CNN’s “State of the Union.” “So, the president seemed to already be changing his story a little bit and say, ‘well, it was all legal.’ ”

Some Republicans contended Sunday that it was of little consequence that Trump was doing business in Russia during the campaign.

“The president is an international businessman; I’m not surprised he was doing international business,” Sen. John Barrasso (R-Wyo.) said on “Meet the Press.” “Cohen is in trouble for lying to Congress. We have a Mueller investigation going on. We need to come to completion on that.”

Asked whether it was fair that voters had not been given a complete picture of Trump’s involvement with Russia in 2016, Barrasso said many factors were involved in the campaign, not just Trump’s business dealings.

“There were so many things involved in the 2016 campaign, it’s hard to point to what one thing influenced voters,” the senator said. “They didn’t want Hillary Clinton; they wanted a new opportunity.”