House Speaker Nancy Pelosi slammed House Republicans and President Trump as "shameful, sad and irresponsible" for calling on Democrat Rep. Adam Schiff of California to resign as head of the House Intelligence Committee. Pelosi's comments came after all nine Republicans on the House Intelligence Committee unveiled a letter Thursday calling for Schiff ouster due to his claims concerning collusion between the Trump campaign and Russian government.

"I think they are just scaredy cats. They just don't know what to do, so they have to make an attack. They did the wrong thing, the American people know that," said Pelosi at her weekly news conference on Thursday. "It's their own insecurity, their own fear of the truth, their fear of the facts."

Special Counsel Robert Mueller's investigation "did not establish that members of the Trump Campaign conspired or coordinated with the Russian government in its election interference activities" according to Attorney General William Barr's summary of the Russia report. Schiff has continued to lead a congressional probe to investigate claims of collusion between the Trump campaign and Russian government, as well as the president's questionable business dealings.

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"They're just plain afraid," added Pelosi of her Republican colleagues. "They're afraid of the truth, they're afraid of competence, they're afraid of a leader who is recognized in our country for being calm, professional and patriotic."

The Republican letter accused Schiff of being "at the center of a well-orchestrated media campaign claiming, among other things, the Trump campaign colluded with the Russian government."

"Your willingness to continue to promote a demonstrably false narrative is alarming," said the letter, which was read aloud by Republican Rep. Mike Conaway. "The findings of the Special Counsel conclusively refute your past and present assertions and have exposed you as having abused your position to knowingly promote false information, having damaged the integrity of this committee, and undermined faith in U.S. government institutions."

Pelosi added that she was proud of the work Schiff has done as chairman of the committee. In a jab at GOP Rep. Devin Nunes, Pelosi said Schiff's performance stood "in stark contrast to the irresponsible, almost criminal behavior of the previous chair of the committee."

The House Speaker also reiterated her call for the Mueller report to be released to the public. And she called into question Attorney General William Barr's credibility due to his past assertions that a sitting president cannot not be indicted.

"We have to see the facts, we have to see what the report is," urged Pelosi.

Meanwhile, Pelosi said Democrats are ready to take their fight with the Trump administration over the future of the Affordable Care Act now that the Justice Department intends to strike down the Obama-era health care law.

"We are focused on meeting the needs of the American people in their lives and that is not what the administration is doing. You would think the Justice Department would be busy vetting reports...instead, what do they do, they're going to court to overturn every single provision of the Affordable Care Act. Not a good use of their time, we'll see them in court," Pelosi vowed.

"We stand ready to make health care better to reach our goal of ever-expanding access to many more people," she added.