Robert S. Mueller III spent more than two years ignoring taunts — tweeted and barked — from President Trump.

But on Wednesday, over the course of six hours, two hearings and in his own understated — and at times juddering — way, the former special counsel finally responded to the president, firmly pushing back on the months-long public relations offensive the president and his team waged to undermine Mueller and his investigators.

Testifying before Congress, he agreed with the assertion from House Intelligence Committee Chairman Adam B. Schiff (D-Calif.) that seeking campaign assistance from a foreign power is “unpatriotic” and “wrong.” He also said he found Trump’s praise of WikiLeaks to be “problematic,” noting Trump’s pro-WikiLeaks statements give “some hope or some boost to what is and should be illegal activity.”

Mueller clarified that his investigation and 448-page, redacted report did not, in fact, “totally exonerate” the president — contrary to Trump’s repeated claims — nor did it say there was no obstruction.

“The president was not exculpated for the acts that he allegedly committed,” Mueller said.

Mueller also defended his investigators, becoming increasingly animated as he said his main hiring criteria was people who could “do the job quickly and seriously and with integrity.” He agreed that it was “generally” true that the Trump campaign built its messaging strategy around stolen documents, lied to cover it up and that the president’s written answers to Mueller’s team were not always truthful, either. And he dismissed Trump’s frequent claims that Russian interference in the 2016 presidential election was a “hoax,” while also rejecting the president’s charge that his investigation was a “witch hunt.”

“It is not a witch hunt,” he said. 

Mueller’s appearance Wednesday on Capitol Hill was hard-fought, painstakingly negotiated and highly anticipated. But, ultimately, his turn as a reluctant and at times uncomfortable witness seemed unlikely to change the political dynamic. Both Democrats and Republicans had largely made up their minds, and the hearings simply allowed them to burrow further into their already entrenched camps.

Even Democrats who favor impeachment acknowledged that Mueller’s performance did not provide the made-for-TV moment for which they had hoped.

“I don’t see it as a seminal moment in time. I really do not,” said Rep. Al Green (D-Tex.), who last week forced a House vote on whether to consider impeaching the president.

Despite Mueller’s pushback against the president and his defense of his own investigation, the testimony may even undercut the party’s push for impeachment and hand Trump and Republicans a new talking point in trying to discredit the two-year probe.

Trump, who spent nearly the entire day watching and tweeting about the cable news spectacle — he did not leave his residence until the afternoon, a senior White House official said — weighed in on the South Lawn on Wednesday afternoon, criticizing Mueller and the Democrats.

Mueller, the president said, did a “horrible job,” both in his public testimony and extensive report. “I don’t think there’s anybody that would say he did well,” Trump added.

He also claimed Mueller’s investigation was a “phony cloud” and argued that the Democrats had further hampered their own political interests by calling on Mueller to testify.

“I think they hurt themselves very badly for 2020,” Trump said, shortly before departing to a fundraiser in West Virginia. “The Democrats lost so big today.”

Democratic leaders had warned their committee members that Mueller might not live up to the hype — one of the main reasons some lawmakers tried to downplay expectations heading into the hearing. But even skeptics did not expect Mueller to so fully refuse to elaborate on any of the details in his report.

“They thought they were going to be able to turn this hearing into a prolonged anti-Trump TV ad, and all they ended up getting was a very ‘low-energy’ witness and a whole lot of disappointment,” said Andy Surabian, a Republican strategist and former Trump White House official.  

Even some pro-impeachment Democrats agreed that Mueller did little to help them make their case to the American public that Trump needs to be ousted from office. 

Sen. Jon Tester (D-Mont.) said that although he supported House Democrats on opening impeachment proceedings to gather more information, he was not sure that the hearing “changed the landscape” to move in that direction. 

“I’m not sure impeachment is the right direction to go, but it’s really in the House’s hands, because it’s not going to go anywhere over here,” Tester said, referring to the Republican-controlled Senate.

Perhaps the bigger problem for the Democratic Party, however, was that Mueller appeared confused at times, stumbling over his answers and frequently imploring his questioners to repeat their queries.

His sometimes halting performance led Republicans to suggest that Mueller was either unfamiliar with the report or — worse — not as mentally sharp as he should be leading such a sweeping investigation of a sitting president.

Mueller, who testified before the House Judiciary Committee in the morning, appeared more forceful and prepared during his testimony before the House Intelligence Committee on Wednesday afternoon. 

Yet Trump allies immediately started questioning the findings of the Mueller report, with some even mocking the Vietnam War veteran, who received a Purple Heart and led law enforcement in the days after the Sept. 11, 2001, terrorist attacks. 

Rudolph W. Giuliani, Trump’s lawyer, said that although he would have preferred that Mueller not publicly testify at all, “it was a great morning for the president.”

Giuliani described Mueller as “a pathetic witness, stumbling, bumbling,” before briefly imitating the “ahhs” and “umms” that peppered his appearance, especially the first session. “It’s not going to move any needles,” Giuliani said. “If anything, it’s going to hurt the Democrats a little bit.”

White House press secretary Stephanie Grisham also offered a scathing assessment of the proceedings during a break between the hearings. 

“The last three hours have been an epic embarrassment for the Democrats,” Grisham said in an email statement she repeated on Twitter. “Expect more of the same in the second half.” 

The immediate upshot for Democratic leaders — who have faced turmoil within their caucus for refusal to begin impeachment proceedings against Trump — was that the hearings appeared to do little to galvanize congressional sentiment. Before the spectacle, many pro-impeachment Democrats were predicting Mueller’s testimony would inspire a new wave of impeachment backers, potentially two dozen or more. 

But by Wednesday afternoon, almost no new Democrats in the House had joined the calls to start proceedings — what Josh Holmes, a former top staffer for Senate Majority Leader Mitch McConnell (R-Ky.), called a “silver lining” for House Speaker Nancy Pelosi (D-Calif.), an impeachment-skeptic.

“If this doesn’t break the fever, nothing will,” Holmes said. “These hearings are an abject disaster for the impeachment caucus, which I suppose is a silver lining for Pelosi.”

In a news conference Wednesday evening, Pelosi again stopped short of endorsing impeachment. “We still have some outstanding matters in the courts,” she said. “It’s about the Congress, the Constitution and the courts.”

In the weeks leading up to the hearing, congressional Democrats heard concerns that the 74-year-old Mueller — who had not testified before Congress in six years — would not be up to the task of answering rapid-fire questioning from 63 lawmakers over six hours. They dismissed those and proceeded to push Mueller’s team to commit to a date and public testimony — and then expanded the hearing timeline by an additional hour.

Many say that move backfired, as Mueller struggled to recall which president nominated him to be a federal prosecutor or, during another answer, to articulate the word he wanted to use — “conspiracy.”

Conservatives seized on Mueller’s shaky testimony. “Dazed and confused” read the headlines on the conservative Drudge Report.

House Freedom Caucus Chairman Mark Meadows (R-N.C.) tweeted that “the more this hearing goes on, the more it becomes painfully clear that not only did Bob Mueller not write his own report — he was barely involved or in control of it at all.”

Meadows, who visited Trump at the White House on Wednesday, said, “I can safely say that Mueller did come up.” The president, Meadows said, “should be happy, given what the expectation was for so many on the Democrat side and what was delivered.”

Judiciary Committee Democrats, however, pushed back on suggestions that they had miscalculated by bringing in Mueller and argued in interviews that their effort was a success. 

“What we established today in the hearing is that we have a felon sitting in the White House. Donald Trump committed multiple crimes of obstruction of justice,” said Rep. Ted Lieu (D-Calif.).   

Not all Republicans were eager to gloat. Sen. Lindsey O. Graham (R-S.C.), a top Trump ally, seemed genuinely upset when asked about Mueller’s performance, pausing for a time before defending Mueller with a cracked voice.

“I like Bob Mueller and the hearing’s confusing, and Bob Mueller has served our nation well for a very long time — and this hearing should not be the judge of his service to our country,” Graham said.

He added: “I’m not going to let this hearing change my opinion of Mr. Mueller.”

Paul Kane, Seung Min Kim, Robert Costa and Erica Werner contributed to this report.