Washington (CNN) As hearings continue in the House impeachment inquiry, President Donald Trump has continued to attack individuals involved in what he considers a purely partisan affair. Since the inquiry started, the President has labeled several people who initially testified behind closed doors, and are now scheduled witnesses in the public impeachment hearings, as "Never Trumpers."

His latest target is Jennifer Williams, an aide to Vice President Mike Pence and a career foreign service officer. Over the weekend, Trump tweeted that Williams "should meet with the other Never Trumpers, who I don't know & mostly never even heard of, & work out a better presidential attack!"

Williams, who is scheduled to testify on Tuesday, stands accused of being a "Never Trumper" alongside former US Ambassador to the Ukraine Marie Yovanovitch, Ambassador Bill Taylor and Lt. Col. Alexander Vindman.

Facts First: There is no public evidence for the President's claims that any of these career government officers were "Never Trumpers," and thus aligned against the President before he won election. Instead, "Never Trumper" is the President's latest line of defense, and a label he tends to apply to anyone he perceives as a threat, regardless of whether it's true.

Here's a break-down of each individual's role within the impeachment inquiry and the facts refuting Trump's accusation that they are a "Never Trumper."