The Justice Department, after weeks of tense negotiations, has agreed to provide Congress with key evidence collected by Robert S. Mueller III that could shed light on possible obstruction of justice and abuse of power by President Trump, the House Judiciary Committee said on Monday.

Through his unrelenting efforts to obstruct the Trump-Russia investigation since its inception, President Donald Trump has inflicted a slow-motion Saturday Night Massacre on the American people, a constitutional nightmare that has lasted two years instead of one night.

The investigation led by Robert S. Mueller III found that neither President Trump nor any of his aides conspired or coordinated with the Russian government’s 2016 election interference, according to a summary of the special counsel’s findings made public on Sunday by Attorney General William P. Barr.Mr. Barr also said that Mr. Mueller’s team drew no conclusions about whether Mr. Trump illegally obstructed justice.