WASHINGTON — Speaker Nancy Pelosi indicated Wednesday night that the House could indefinitely delay sending the articles of impeachment against President Trump to the Senate, leaving ambiguous the timing of a trial to decide whether to acquit him or convict and remove him from office.
After historic nearly party-line votes to impeach Mr. Trump for two articles, abuse of power and obstruction of Congress, Ms. Pelosi told reporters that she would hold the articles back until it was clearer that the upper chamber would give the case a fair hearing. The strategy suggested she was keeping the charges as leverage in a coming negotiation over the terms of a Senate trial.
But it could leave the matter in limbo until early January, delaying the start of a trial for an unknown period of time.
“We will make our decision as to when we are going to send it when we see what they are doing on the Senate side,” Ms. Pelosi said. “So far, we have not seen anything that looks fair to us.”
The decision injected a new element of uncertainty into an impeachment process that has already roiled the Capitol and promises profound political implications for Mr. Trump, his party and the Democrats.
With Mr. Trump and his allies said to be interested in a speedy trial and acquittal, Ms. Pelosi believes slowing down the proceeding could force Senate Republicans to set procedures the Democrats find more favorable to their case, according to Democratic officials who spoke on the condition of anonymity to discuss internal deliberations.
But it is not at all clear that Ms. Pelosi holds much leverage over Senator Mitch McConnell, Republican of Kentucky, who as majority leader has broad power to determine the contours of the trial. An adviser to Mr. McConnell, Josh Holmes, signaled the majority leader was in no rush to try the president for impeachable offenses, writing on Twitter that the maneuver “might be the greatest compliment McConnell has ever received.”
“They are seriously entertaining holding a grenade with the pin pulled rather than facing what happens when they send it over McConnell’s wall,” Mr. Holmes said.
Democrats in the Senate had already complained that Mr. McConnell was trying to ram through the president’s acquittal by refusing to call witnesses or obtain new evidence. They also took issue with Mr. McConnell’s assertions that it was not his role to act as an “impartial juror” during a trial and that he would closely coordinate any trial with the White House Counsel’s Office.
“This is what I don’t consider a fair trial,” Ms. Pelosi said on Wednesday.
Representative Earl Blumenauer, Democrat of Oregon, said he had spoken to at least 40 Democrats who were concerned that Mr. McConnell would not conduct a fair trial, and who wanted Ms. Pelosi to delay sending the articles to the Senate until she learned more about how the proceedings would move forward.
“What is gained by accelerating this process?” he asked. He said Democrats should “let the speaker work her magic” to “get some sort of assurance, if it’s possible, that there will be a level playing field.”
In addition, some Democrats — including some of the chamber’s most progressive lawmakers — have advocated simply never sending the articles of impeachment to the Senate, to deny Mr. Trump an almost certain acquittal in the Republican-controlled chamber, where a two-thirds vote — 67 senators — are needed to convict. Ms. Pelosi has not ruled that out, but House leaders are not seriously contemplating that course, the Democratic officials said.
The Constitution does not dictate how the process of transmitting articles of impeachment from the House to the Senate should work. It says only that the House has “the sole power of impeachment” and that the Senate, “shall have the sole power to try all impeachments.”
But Ms. Pelosi’s hesitation departs from the precedent set by the only modern presidential impeachment.
In December 1998, a group of Republicans immediately marched the articles of impeachment against President Bill Clinton across the Capitol to the Senate after the House vote almost exactly 21 years ago. Because the Senate was not in session, the trial did not begin until early January.
The speaker indicated she would also wait to appoint impeachment managers, the House members responsible for prosecuting the case in the Senate, until the matter was resolved.
“We cannot name managers until we see what the process is on the Senate side, and I would hope that would be soon” Ms. Pelosi said.
Representative David Cicilline, Democrat of Rhode Island, said he did not expect Ms. Pelosi to hold onto the articles indefinitely. But he said Mr. McConnell’s close coordination with the White House “makes a mockery of the trial.”
“I think everyone needs to be assured that there is a process in place that will treat these very serious impeachment articles with the gravity they deserve,” he said.
Still, if there is no resolution on Thursday, a stalemate could easily drag on for weeks.
Under the rules adopted to consider the articles on Wednesday, the House must hold a separate vote allowing Ms. Pelosi to appoint the impeachment managers and transmit the articles to the Senate. The House is scheduled to leave Washington at the end of the week for the Christmas and New Year’s holidays, meaning if she does not take the action by then, the fate of the articles could be left unresolved until early January, when Congress reconvenes in the capital.
Sheryl Gay Stolberg contributed reporting.