Richard Painter said there was "impeachable evidence" against the president.
MSNBC host Joe Scarborough referred to President Donald Trump's actions over the weekend as "Nixonian."
The pro-Trump sign in Maryland has been the subject of numerous complaints from concerned residents.
“Now is not the time to consider articles of impeachment," House Minority Leader Nancy Pelosi and Democratic Minority Whip Steny Hoyer previously stated.
The messages “Trump Is a Serial Sexual Assaulter,” “Groper-in-Chief” and “Morally Unfit" were also to be projected on Trump's Washington, D.C., hotel.
The Trump impeachment guide contains "steps we must take to remove one of the gravest dangers our country has ever confronted.”
Senators Lindsey Graham and Jeff Flake, both of whom have leveled criticism against the president before, indicated that firing Mueller would be impeachable conduct.
Trump’s failure to respond to Russian interference in the 2016 election is “a betrayal of his oath of office,” Need to Impeach founder Tom Steyer said.
A second woman has accused Supreme Court Justice Clarence Thomas of sexual assault, and a campaign to impeach him is looming.
“I liken it to being on a wild horse,” Steyer said of America under Trump.
“As every day goes by, we are at greater risk of total annihilation,” psychologist John Gartner said.
"We must take stand against this president and his bigoted comments,” Al Green said.
Texas Democrat Al Green has said that he will force another vote on impeaching Trump in the wake of the president’s latest controversial remarks.
One of the co-authors of the amendment believes impeaching President Trump is a far stronger means of removing him from office.
The amendment has become a hot topic under Trump following the publication of Fire and Fury, a Michael Wolff book that said nearly the entire White House staff is worried about Trump's fitness for office and mental stability.
Could Michael Wolff's bombshell revelations sink the Trump presidency?
The Democrats' efforts to open impeachment hearings in the House have failed so far.
"That doesn't mean that impeachment is a reasonable thing to pursue," Congressman John Yarmuth said.
The likelihood of Trump facing impeachment also could rise if he fires Russia probe special counsel Robert Mueller.
Democratic congressman Ted Lieu is warning President Donald Trump about possible impeachment if he fires investigators looking into his campaign's contacts with Russia.
"This is a critical time in our nation’s history," Nadler said.