WATCH: Rep. Liz Cheney says ‘dam has begun to break’ due to the Jan. 6 investigation

The vice chair of the Jan. 6 committee says “doors have opened, new subpoenas have been issued and the dam has begun to break″ due to the panel’s continuing investigation and its successful effort to overcome reluctance from witnesses.

Watch Cheney’s remarks in the player above.

Republican Rep. Liz Cheney of Wyoming says at the committee’s prime-time hearing that Donald Trump’s goal was to halt or delay the congressional certification of Joe Biden’s election victory, and that the then-president tried to strong-arm his own vice president, state election officials and the Justice Department.

WATCH: Jan. 6 Committee hearings – Day 8

Cheney says that on Jan. 6, 2021, the only thing that was succeeding was the “angry armed mob that President Trump sent to the Capitol. … That mob was violent and destructive, and many came armed.”

She says that on that day, Trump for hours chose not to answer pleas from Republican lawmakers to intervene and stop the violence, and never picked up the phone to request the help from the military or from law enforcement.

Cheney says “he refused to do what every American president must.”