WASHINGTON — Rep. Mike Doyle got a months-long wish granted on Tuesday when House Speaker Nancy Pelosi announced a formal impeachment inquiry into President Donald Trump.

Hours before Ms. Pelosi, D-Calif., said the House would act because Mr. Trump had “seriously violated the Constitution,” Mr. Doyle, a Democrat from Forest Hills, repeated his call for an impeachment inquiry of the president.

Mr. Trump is accused of pressuring the president of Ukraine to investigate former Vice President Joe Biden, the leading Democratic challenger in the upcoming 2020 presidential election. The alleged misconduct — the subject of a whistleblower complaint that surfaced last week — is “mind-boggling,” Mr. Doyle wrote.

“That the president of the United States would withhold Congressionally directed funds to an ally in need, in order to compel it to smear a political rival, seems to amount to blatant extortion for personal political gain,” Mr. Doyle wrote. Mr. Trump has acknowledged raising Mr. Biden’s name in his conversation with the Ukranian president but denied that it was tied to withholding funds.

Another Pittsburgh-area Democrat had a different take: Wait and see.

Rep. Conor Lamb, D-Mt. Lebanon, said he will withhold his support for an impeachment inquiry until he gets more evidence. Reached on Tuesday after the impeachment inquiry was announced, Mr. Lamb referred to a statement in which he called on the acting director of national intelligence, Joseph Maguire, to release all of the information regarding the complaint.

“As I said yesterday, we need to get the full text of the whistleblower complaint by Thursday, not just the transcript of one phone call,” Mr. Lamb said in a statement provided by his office.

“It appears that we will learn more facts in the coming days, and I’ll have more to say after that,” he said.