No Democrat was in more demand Wednesday than Rep. Al Green (Tex.) — the seven-term Democrat from Houston who held a hometown news conference two days before calling for the impeachment of President Trump. Then came allegations that Trump had pressured the FBI director to beg off a criminal investigation of his then-national security adviser — and then came the media.

Green delivered a morning floor speech on impeachment (“with a heavy heart, with a sense of duty”), then spent nearly an hour just outside the House chamber, walking from camera to camera near the Capitol’s statue of Will Rogers, where TV networks set up their satellite links.

“It’s about the fact that the president has committed obstruction of justice,” Green, a former trial lawyer, said in an interview. “It is indisputable that he fired the FBI director. It is indisputable that he said he considered the investigation that was taking place — of the president — when he fired him. And it’s indisputable that he went on to tweet what might be considered intimidation, words that are intimidating.”

For much of a frenzied day, Democrats and Republicans were asked not just whether there needed to be further investigations of the president, but whether impeachment, a power Congress has used against just three of its 45 presidents, was on their minds.

It was unclear how the Justice Department’s decision to appoint Robert S. Mueller III as a special counsel to oversee allegations of Russian meddling in the election would affect such talk. As of earlier Wednesday, neither party’s leaders wanted to talk about impeachment. But neither party could seem to avoid it.

“I think that we ought to keep our focus on finding out the facts,” said Rep. Adam B. Schiff (Calif.), the ranking Democrat on the House Intelligence Committee, at a morning news conference meant to tout the Democrats’ campaign to form an independent commission on the FBI scandal. “No one ought to, in my view, rush to embrace the most extraordinary remedy that involves the removal of the president from office.”

The impeachment talk had already begun at the fringes of the Democratic Party before this week — Rep. Maxine Waters (D-Calif.) was leading the charge. But despite the Mueller announcement, the noise grew louder after news that ousted FBI Director James B. Comey took notes of his conversation with Trump, during which the president asked Comey to drop the investigation of former national security adviser Michael Flynn, according to Comey’s associates.

As with so much of Congress’s agenda, whether to talk impeachment seems to have been a choice that outside forces had already made for lawmakers. At a Monday night town hall sponsored by CNN, House Democratic leader Nancy Pelosi (D-Calif.) was prodded on the impeachment question, and she stayed with the party’s message: an investigation would uncover facts, and impeachment made no sense without it.

“If you are talking about impeachment, you are talking about, ‘What are the facts?’ ” she said. “What are the facts that you would make a case on? What are the rules that he may have violated? If you don’t have that case, you are just participating in more hearsay.”

For that, Pelosi was flayed on Twitter by left-wing accounts. And by midweek,…