CNN
Now playing
01:31
Swalwell: Trump keeps taking wrecking ball to rule of law
US Representative Marjorie Taylor Greene, Republican of Georgia, leaves her office on Capitol Hill on February 4, 2021 in Washington, DC.
NICHOLAS KAMM/AFP/Getty Images
US Representative Marjorie Taylor Greene, Republican of Georgia, leaves her office on Capitol Hill on February 4, 2021 in Washington, DC.
Now playing
03:51
Marjorie Taylor Greene launching 'America First' caucus
US President Joe Biden delivers remarks on Russia at the White House in Washington, DC on April 15, 2021. - The United States announced sanctions and the expulsion of 10 Russian diplomats Thursday in retaliation for what Washington says is the Kremlin's US election interference, a massive cyberattack and other hostile activity.
JIM WATSON/AFP/Getty Images
US President Joe Biden delivers remarks on Russia at the White House in Washington, DC on April 15, 2021. - The United States announced sanctions and the expulsion of 10 Russian diplomats Thursday in retaliation for what Washington says is the Kremlin's US election interference, a massive cyberattack and other hostile activity.
Now playing
02:22
White House backtracks on refugees decision after criticism
Biden speaks from the Treaty Room in the White House on April 14, 2021 in Washington, DC.
Andrew Harnik/Pool/Getty Images
Biden speaks from the Treaty Room in the White House on April 14, 2021 in Washington, DC.
Now playing
02:44
'National embarrassment': Biden reacts to mass shootings
MOSCOW, RUSSIA - APRIL 15:  Russian President Vladimir Putin (L) talks to talks to Foreign Minister Sergey Lavrov during a meeting with Uzbekistan President Islam Karimov in the Kremlin on April 15, 2013 in in Moscow, Russia. Karimov is on a state visit to Russia. (Photo by Sasha Mordovets/Getty Images)
Sasha Mordovets/Getty Images
MOSCOW, RUSSIA - APRIL 15: Russian President Vladimir Putin (L) talks to talks to Foreign Minister Sergey Lavrov during a meeting with Uzbekistan President Islam Karimov in the Kremlin on April 15, 2013 in in Moscow, Russia. Karimov is on a state visit to Russia. (Photo by Sasha Mordovets/Getty Images)
Now playing
02:07
Russia to expel 10 US diplomats in 'tit-for-tat response' to Biden sanctions
Now playing
03:10
Avlon: Here's what we know 100 days since the Capitol riot
A Russian flag flies next to the US embassy building in Moscow on October 22, 2018. - US national security advisor John Bolton is in Moscow holding meetings with senior Russian officials following Washington's weekend announcement of withdrawal from the Cold War-era Intermediate-Range Nuclear Forces Treaty, known as the INF. (Photo by Mladen ANTONOV / AFP)        (Photo credit should read MLADEN ANTONOV/AFP via Getty Images)
Mladen Antonov/AFP/Getty Images
A Russian flag flies next to the US embassy building in Moscow on October 22, 2018. - US national security advisor John Bolton is in Moscow holding meetings with senior Russian officials following Washington's weekend announcement of withdrawal from the Cold War-era Intermediate-Range Nuclear Forces Treaty, known as the INF. (Photo by Mladen ANTONOV / AFP) (Photo credit should read MLADEN ANTONOV/AFP via Getty Images)
Now playing
02:17
Political scientist: US-Russia relations are in the toilet
Now playing
03:05
Avlon calls for training and reform in police departments
WASHINGTON, DC - JUNE 13: Rep. Michelle Lujan Grisham (D-NM) speaks during a news conference on immigration to condemn the Trump Administration's "zero tolerance" immigration policy, outside the US Capitol on June 13, 2018 in Washington, DC. (Photo by Toya Sarno Jordan/Getty Images)
Toya Sarno Jordan/Getty Images
WASHINGTON, DC - JUNE 13: Rep. Michelle Lujan Grisham (D-NM) speaks during a news conference on immigration to condemn the Trump Administration's "zero tolerance" immigration policy, outside the US Capitol on June 13, 2018 in Washington, DC. (Photo by Toya Sarno Jordan/Getty Images)
Now playing
02:39
Governor settles with former campaign staffer who accused her of sexual mistreatment
pool/cnn
Now playing
01:56
Hear what Dr. Gupta said when Cruz went maskless before
Now playing
02:30
Biden's decision to withdraw from Afghanistan is personal for this lawmaker
President Joe Biden speaks from the Treaty Room in the White House on Wednesday, April 14, 2021, about the withdrawal of the remainder of U.S. troops from Afghanistan.=
Andrew Harnik/AP
President Joe Biden speaks from the Treaty Room in the White House on Wednesday, April 14, 2021, about the withdrawal of the remainder of U.S. troops from Afghanistan.=
Now playing
02:10
Why Biden made his Afghanistan announcement in this particular room
U.S. President Joe Biden speaks from the Treaty Room in the White House about the withdrawal of U.S. troops from Afghanistan on April 14, 2021 in Washington, DC. President Biden announced his plans to pull all remaining U.S. troops out of Afghanistan by September 11, 2021 in a final step towards ending America's longest war.
Andrew Harnik/Pool/Getty Images
U.S. President Joe Biden speaks from the Treaty Room in the White House about the withdrawal of U.S. troops from Afghanistan on April 14, 2021 in Washington, DC. President Biden announced his plans to pull all remaining U.S. troops out of Afghanistan by September 11, 2021 in a final step towards ending America's longest war.
Now playing
01:03
Biden: It's time to end the forever war
Kinzinger
CNN
Kinzinger
Now playing
05:56
What Republican lawmaker fears after US troops leave Afghanistan
CNN
Now playing
02:45
Sen. Bernie Sanders: Trump was right about this
Rep. Matt Gaetz, R-Fla., questions witnesses during a House Armed Services Committee hearing on Capitol Hill, Wednesday, April 14, 2021, in Washington.
Manuel Balce Ceneta/AP
Rep. Matt Gaetz, R-Fla., questions witnesses during a House Armed Services Committee hearing on Capitol Hill, Wednesday, April 14, 2021, in Washington.
Now playing
02:59
Women detail late-night parties with Gaetz
(CNN) —  

The impeachment of President Donald Trump suddenly looks like much more than just a theoretical possibility.

Democrats on Monday will launch an “abuse of power” investigation that could be easily transformed into an even more serious process, with an expansive demand for documents from Trump’s government, his family and even his real estate empire.

The President reacted to his worsening plight with a vehement defense on Sunday, after a week in which testimony from his ex-lawyer Michael Cohen deepened his political vulnerability and ahead of the expected filing soon of special counsel Robert Mueller’s report.

“Presidential Harassment by ‘crazed’ Democrats at the highest level in the history of our Country. Likewise, the most vicious and corrupt Mainstream Media that any president has ever had to endure,” Trump tweeted Sunday night.

House Judiciary Committee Chairman Jerry Nadler, who would eventually lead any impeachment proceedings, on Sunday signaled a significant escalation into congressional inquiries into the President.

The New York Democrat plans on Monday to request documents from 60 people and entities close to Trump, including from the Department of Justice, the White House and the Trump Organization.

The document trawl will be used “to present the case to the American people about obstruction of justice, about corruption and abuse of power,” Nadler said on ABC News’ “This Week” on Sunday.

Nadler stuck to the House Democratic position that impeachment “is a long way down the road,” apparently in order to avoid Republican arguments that the decision has already been made to try to oust Trump. The document requests are not taking place under the auspices of an official impeachment investigation.

But Nadler said nevertheless that he believes the President had obstructed justice, a potentially impeachable offense.

And given his responsibilities and powers, the warning from Nadler took the President’s political and legal nightmare to a new plane, and opened a new, more serious stage of the showdown between House Democrats and Trump.

It was the latest sign that investigations sparked by accusations that Trump’s campaign team cooperated with Russian election meddling has mushroomed into a relentless examination of Trump’s political, personal and business life.

The latest blow to the President further intensified pressure on the White House as Washington waits for another shoe to drop — with Mueller expected to file his long awaited report from Monday onward.

The Nadler investigation, along with parallel probes into Trump’s presidency by the House Oversight and Intelligence committees means that the structure of a political investigation into the President based in Congress is now in place, alongside the legal inquiries led by Mueller and prosecutors in New York and other jurisdictions.

Trump showing signs of stress

In the last week, partly through Cohen’s testimony, it has become clear that even if the special counsel does not find direct wrongdoing by the President, Trump’s legal troubles will linger deep into his presidency and probably beyond.

Trump is showing increasing signs of stress at being surrounded.

He spent much of the weekend laying out a likely defense should any of the multiple probes find him guilty of wrongdoing and bolstering his stranglehold on the Republican Party that could eventually be key to saving his presidency in a Senate trial if House Democrats opt for impeachment.

“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!” Trump tweeted Sunday.

In a mostly unscripted two-hour speech to the Conservative Political Action Conference on Saturday — one of the most demagogic and inflammatory appearances of his presidency, Trump lacerated Mueller and his investigation.

“So now we’re waiting for a report, and we’ll find out … who we’re dealing with … We’re waiting for a report by people that weren’t elected,” Trump said at CPAC.

“You put the wrong people in a couple of positions and they leave people for a long time that shouldn’t be there, and all of a sudden, they’re trying to take you out with bullshit, OK,” Trump said.

Trump also sketched a defense for two potential areas of vulnerability: his call for Russia to find Hillary Clinton’s missing emails during the 2016 campaign and his firing of former FBI Director James Comey in 2017.

He said he was being “sarcastic” when he asked Russia to find Clinton’s emails and was having fun with his audience.