This week’s impeachment hearings will feature a lineup of firsthand witnesses, including Army Lt. Col. Alexander Vindman, the National Security Council’s director for European Affairs, who reportedly confronted the White House’s “irregular” channel about its attempts to pressure Ukraine into investigating Joe Biden.

Vindman’s first closed-door testimony warranted a good amount of criticism from conservatives concerned about the “unmistakable disdain” Vindman and his lawyer reportedly expressed toward Republican members of Congress. This friction will likely be on display once again during Vindman’s testimony on Tuesday. But Republicans shouldn’t let Vindman’s alleged antagonism (key word: “alleged”) get in the way of the facts.