The Democratic committee chairman leading the House impeachment hearing is highlighting verbal attacks that President Donald Trump and his defenders have made against two government officials who are testifying.

Rep. Adam Schiff spoke on Nov. 19 as part of the impeachment inquiry into President Donald Trump. Watch in the player above.

As Tuesday’s hearing began, California Rep. Adam Schiff mentioned Trump’s tweet in which he accused Vice President Mike Pence adviser Jennifer Williams of being a never-Trumper.

Schiff also criticized “scurrilous attacks” against Lt. Col. Alexander Vindman, who he noted “shed blood for America.” He said he hoped members of the House Intelligence Committee would not attack him.

MORE: A guide to the impeachment hearings

The top Republican on the committee is California Rep. Devin Nunes.

He accused Democrats of hiding the whistleblower whose report triggered the impeachment investigation in their “own witness protection program.” And he says witness testimony so far has been based on second- and third-hand accounts of conversations.