Schiff, a lawyer who has served in Congress since 2001, ranged far and frequently across the media landscape in interviews about the Mueller investigation. In his sober, mild-mannered style, Schiff at times came close to sounding like he believed Trump had broken the law, Republicans said.
More than any other example, Republicans on Monday pointed to a March, 2017 appearance on MSNBC in which Schiff said "there is more than circumstantial evidence now" of a relationship between Russia and Trump's associates. In December of that year, Schiff said on CNN: "The Russians offered help, the campaign accepted help. The Russians gave help and the president made full use of that help. That is pretty damning, whether it is proof beyond a reasonable doubt of conspiracy or not."
And in May of last year, Schiff said on ABC that the Russian trolling of Democratic National Committee emails is "like Watergate in the sense that you had a break in at the Democratic headquarters, in this case a virtual one, not a physical break in, and you had a president as part of a cover up."
Schiff was defiant this week, repeating his assertion that evidence of collusion is in "plain sight" and leading the Democrats' call to have the Justice Department release Mueller's full report. He said he accepts Mueller's conclusion that he could not prove a criminal conspiracy with Russia, but insisted that his committee's investigative work will go on.
"All we have right now is a four-page summary by the attorney general," he told Lily Jamali in an interview Tuesday on the California Report. "And this was someone who was picked by the president to be attorney general because of his hostility to the investigation ... We need to see the full report. We need to see the full evidence on obstruction. We need to see the full evidence on conspiracy. "
Schiff is far from the only Democrat to use provocative rhetoric about Trump, but his statements in particular, seem to have touched a nerve with the president and other key Republican leaders.
"Now we find out that none of that is true," House Republican leader Kevin McCarthy of California told The Associated Press. "He should first apologize to the American public and he should step back from the chairmanship."
McCarthy added: "It's over. When are they going to take an answer for an answer? There's no more rocks to be overturned."
Presidential counselor Kellyanne Conway went further.
"This man leads the Intelligence Committee in the House," Conway said on Fox News Channel. "He ought to resign today."
But there was no sign of that happening.
House Speaker Nancy Pelosi, D-Calif., said the calls to remove Schiff were "absolutely ridiculous." She consulted with Schiff and other committee leaders over the weekend as Attorney General William Barr notified Congress of Mueller's report and summarized the details.
Barr wrote that Mueller did not find collusion. On obstruction, the Mueller report laid out evidence but did not make a finding implicating Trump or exonerating him. That move effectively punted the obstruction question to Congress, where Democrats control the House and Republicans run the Senate.
A Pelosi aide said Schiff was being attacked because he's done "an outstanding job."
"Democrats aren't going to be intimidated by the White House or Congressional Republicans," spokeswoman Ashley Etienne said. "We're not going to be distracted from securing the release of the full Mueller report and the underlying evidence, and we will continue to pursue legitimate oversight because that's what the Constitution requires."
Schiff this week appeared ready to forge ahead with an investigation into the Trump Organization.
Schiff, for example, wants to lead a public hearing featuring Felix Sater, a Soviet emigre who befriended Trump in the 2000s and helped push the Trump Tower Moscow project during the 2016 presidential campaign.
"Naturally, they don't want our Congress to do oversight," said Schiff. "But we're not going to be intimidated by these tactics, which for me are nothing new. And we're going to plow forward."
Associated Press writers Alan Fram and Mary Clare Jalonick contributed to this report.