Senate Republicans are backing off initial, ironclad opposition to witnesses in the upcoming trial to adjudicate two articles of impeachment against President Trump.

As House Democrats approved charges of abuse of power and obstruction of Congress in mid-December, most Senate Republicans signaled they were inclined to conclude an impeachment trial without witness testimony immediately following arguments from the defense and prosecution. But having agreed this week to broad contours for trial procedure, Republicans are declining to rule out witnesses, saying it depends on what they hear from House prosecutors and the White House defense.