WASHINGTON — The escalating impeachment drama between Congress and the White House that has all but doomed hopes of most legislative progress this fall has instead enhanced the prospects for approval, within weeks, of one major initiative: a sweeping new trade agreement among the United States, Canada and Mexico.

[Here is what happened in the Trump impeachment inquiry today.]

Top lawmakers in both parties and others closely following the talks said that substantial progress had been made in resolving the sticking points, and that a decisive House vote on the accord to replace the North American Free Trade Agreement could occur before Congress departed for Thanksgiving.

The deal may be a rare bright spot in an otherwise dysfunctional dynamic that has taken hold in the capital, and it owes its progress to a coincidence of timing, productive negotiations that have unfolded behind closed doors for months and political necessity for two parties that each has distinct reasons to hope it succeeds.

“We are on a path to yes,” Speaker Nancy Pelosi told reporters last week in one of the strongest signals yet that she would put the full weight of her leadership behind passage of the agreement, the United States-Mexico-Canada Agreement.