On Friday morning, the phrase #RightMatters — from the last line of Mr. Schiff’s Thursday speech — was trending as a hashtag on Twitter. The Daily Beast declared that the remarks “will go down in history.” Ryan Knight, a progressive activist, called it “a closing statement for the ages.” Video of the speech quickly went viral. Liberals lavished him with praise.

“I am in tears,” wrote Debra Messing, the “Will & Grace” actress and outspoken Trump critic. “Thank you Chairman Schiff for fighting for our country.”…

Regardless of the risk, it was clear on both sides of the aisle — and to experienced prosecutors who watched — that after a long day of complicated and sometimes monotonous testimony, Mr. Schiff’s oratory broke through. Mr. Schiff apparently thought so himself. He posted the last eight minutes, the most dramatic part of his speech, on Twitter Thursday night, and by Friday evening it had been viewed 5.9 million times.

“Sometimes when Schiff steps to the mic I think he’s a little scripted,” Ms. Milgram said. “I did not feel that last night. I thought it was the most authentic I have seen him. He sort of crossed into another level.”