CHICAGO (CBS) — House Minority Leader Nancy Pelosi (D-Calif.) blasted President Donald Trump and House Republicans for their decision to release a controversial four-page memo alleging abuse of surveillance authority by the Justice Department and the FBI, saying it could ultimately cause a “constitutional crisis.”

“He has abdicated his responsibilities as commander in chief to protect the American people by protecting our intelligence sources and the rest,” she said of Trump. ““If the president uses this fake, horrible release of distorted intelligence as an excuse to fire [deputy attorney general Rod] Rosenstein or [special counsel Robert] Mueller, it could lead to a constitutional crisis.”

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Trump announced Friday afternoon he was declassifying the memo, which was prepared by Republican staff of the House Intelligence Committee.

“The GOP memo is a disgrace,” Trump said in the Oval Office while meeting with a group of North Korean defectors. “It was declassified and let’s see what happens…But a lot of people should be ashamed.”

The president suggested that the FBI and Justice Department have favored Democrats over Republicans in the process that led to the release of the Republican memo alleging abuses of a surveillance law. Trump tweeted that they have “politicized the sacred investigative process” but added that “rank & file are great people.”

In Chicago for a town hall meeting on the Trump tax plan, Pelosi also called House Intelligence Committee Chairman Rep. Devin Nunes (R-Calif.) a “stooge for the president.”

Pelosi noted Nunes was supposed to have recused himself from the Russia investigation last year, and she said he should resign for releasing what she called a release of “distorted intelligence.”

“He should not be the chairman of the committee,” Pelosi said.

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Nunes said his committee has discovered “serious violations of the public trust” and that Americans have a right to know when crucial institutions “are abusing their authority for political purposes.”

“Our intelligence and law enforcement agencies exist to defend the American people, not to be exploited to target one group on behalf of another,” he said in a statement. “It is my hope that the Committee’s actions will shine a light on this alarming series of events so we can make reforms that allow the American people to have full faith and confidence in their governing institutions.”

CBS News’ Jeff Pegues reports that the memo focuses in part on the Foreign Intelligence Surveillance Act (FISA) warrants that authorized the surveillance of former Trump campaign foreign policy adviser Carter Page. Federal law enforcement sources as well as congressional sources briefed on the intelligence during the 2016 campaign have said that well before Page joined the Trump campaign, there were concerns about his contacts with Russian spies. The memo looks to connect information gathered for the Trump “dossier” alleging connections between Donald Trump and Russia, to those FISA warrants.

Pelosi said Republicans “cherry-picked” information about the Russia investigation in an effort to thwart the federal probe of Russia’s interference in the 2016 elections, and their ties to the Trump campaign.

“It’s appalling. It’s a misrepresentation. It isn’t even the release of intelligence material. It’s a release of a distortion of it,” Pelosi said. “They’re not representing the facts to the American people, and yet the president has given it his imprimatur. This is unprecedented to the nth degree.”

In a tweet, former FBI Director James Comey called the memo “dishonest and misleading.”

U.S. Sen. Dick Durbin (D-Ill.) also took to Twitter to criticize the release of the memo.

“Using the Nunes Memo as a pretext to fire Rod Rosenstein, Robert Mueller, or other DOJ leadership would clearly be an attempt to obstruct justice in the Russia investigation,” Durbin stated.

Durbin’s post includes a letter to the president, warning him that using the memo as an excuse to fire Rosenstein, Mueller, or other Justice Department officials “could result in a constitutional crisis of the kind not seen since the Saturday Night Massacre.”

The senator was referring to former President Richard Nixon’s orders to fire special prosecutor Archibald Cox in the midst of the Watergate scandal in 1973. That order led to the resignations of Attorney GeneralElliot Richardson and Deputy Attorney General William Ruckelshaus.