Nadler said he believes the president has obstructed justice during his two years in office.
He said: "I am an innocent man being persecuted by some very bad, conflicted & corrupt people in a Witch Hunt that is illegal & should never have been allowed to start - And only because I won the Election!"
In building a case against the 45th USA president, Nadler pointed to Trump's firing of former FBI Director James Comey in May 2017, while the latter was in the process of investigating whether Russian Federation meddled in the 2016 United States presidential election. He - he's dangled pardons, he's threat - he's intimidated witnesses.
During his appearance on the ABC show "This Week", New York Rep. Jerrold Nadler told host George Stephanopoulos that he meant to issue document requests to more than 60 people as the House Judiciary Committee (which Nadler chairs) begins to investigate Trump's numerous scandals, according to Politico.
Mr Nadler isn't calling the inquiry an impeachment investigation but said House Democrats, now in the majority, are simply doing "our job to protect the rule of law" after Republicans during the first two years of Trump's term were "shielding the president from any proper accountability".
Sen. Mark Warner, the top Democrat on the Senate Intelligence Committee, told CNN that after hearing Cohen's testimony, "We've got to dig deeper" about the extent to which Trump pursued construction of a skyscraper in Moscow during the 2016 campaign even as he told voters he was not involved in any Russian business deals.
"We shouldn't be impeaching for a political reason, and we shouldn't avoid impeachment for a political reason", Speaker of the House Nancy Pelosi, a Democrat who represents California, told NBC News in January. He said Republican lawmakers "threatened to impeach people in Justice Department, they threatened the - the Mueller investigation. But we're going to initiate proper investigations", Judiciary Committee Chairman Jerrold Nadler said.More news: The Sunday Edition: President Donald Trump Tweetstorm
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"Before you impeach somebody, you have to persuade the American public that it ought to happen", he finally said.
The committee chief noted that talk of impeachment was too soon, however.
Since taking power in the wake of November's midterm elections, House Democrats have vowed to investigate Trump's presidency and business as they await the special counsel Robert Mueller investigation's findings.
When asked if he believed Trump was guilty of obstruction of justice, Nadler responded that "Yes I do. But this investigation goes far beyond collusion", he said. Nadler said that on Monday the committee will release the list of people and organizations it would request documents from.
Also last week, House Ways and Means Committee Chairman Richard Neal, D, asked his staff to begin preparing a request for Trump's past tax returns to be submitted to the Treasury Department in the coming weeks. "You have to persuade enough of the - of the opposition party voters, Trump voters, that you're not just trying to..."
Nadler said he has made no determination on whether to proceed with impeachment. We may not get there.