Wyoming Republican Rep. Liz Cheney shamed conservatives who have attacked the White House official who is testifying before House impeachment investigators on his concerns over President Trump’s July phone call with Ukrainian President Volodymyr Zelensky.

Lt. Col. Alexander Vindman, an active military member and Purple Heart recipient, registered multiple internal complaints about Trump’s treatment of Ukraine and how he believed it could be harmful to national security. A number of conservative voices, including Fox News’ Laura Ingraham and former GOP Rep. and current CNN contributor Sean Duffy, questioned his credibility because he was born in Ukraine.