Senator Mitch McConnell, the Republican leader, said on Tuesday that the mob that stormed the Capitol on Jan. 6 had been “provoked by the president and other powerful people,” stating publicly for the first time that he holds Trump responsible for the insurrection attempt.

“The mob was fed lies,”McConnell said, referring to attempts by Trump to overturn the election based on bogus claims of voter fraud. “They were provoked by the president and other powerful people. And they tried to use fear and violence to stop a specific proceeding of the first branch of the federal government which they did not like.”

McConnell made the remarks on his last full day as majority leader, speaking on the eve of President-elect Joseph R. Biden Jr.’s inauguration and as the Senate was bracing to receive a single article of impeachment from the House charging Trump with “incitement of insurrection.”

This could aid in convincing at least 17 Republicans to join the Democrats in a bipartisan conviction of Trump. It also has consequences for Senators Ted Cruz of Texas and Josh Hawley of Missouri, both of whom aided in the insurrection attempt.