Lt. Col. Vindman says he never thought he'd have to testify in front of Congress. But he was the center of attention on Tuesday as he described the Trump-Zelensky phone call as "inappropriate" and "improper." He added "I couldn't believe what I was hearing." His emotional testimony - including a reassurance to his Dad that he was safe from retribution - highlighted a revelatory day as three other witnesses appeared in public hearings. Zachary Wolf, senior writer and publisher of the Impeachment Watch Newsletter, guests hosts and makes sense of a consequential day with CNN national security reporter Kylie Atwood and CNN political and national security analyst David Sanger.

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