'Now we see why' Trump blocked Bolton from testifying -- and Republicans are barring witnesses: Adam Schiff
House Intelligence Committee Chair Adam Schiff (screengrab)

House Intelligence Committee Chairman Adam Schiff (D-CA) is one of the handful of members of Congress who have served as managers for President Donald Trump's impeachment trial. He has not only navigated the past week of the trial, but he conducted the first major hearing.

After the New York Times revealed key facts from former national security adviser John Bolton's upcoming book, Schiff said that it was clear the information Bolton has is why Trump blocked him from testifying.

“I think you have to for the sake of the office,” Trump told Fox News’s Laura Ingraham when she asked if he would block Bolton.

“Especially a national security adviser,” he went on. “You can’t have him explaining all of your statements about national security concerning Russia, China, and North Korea — everything. We just can’t do that.”

Schiff tweeted Sunday that it's clear what Bolton knows is something Trump wants to hide from Americans.

"The President blocked our request for Bolton’s testimony. Now we see why," said Schiff. "Bolton directly contradicts the heart of the President’s defense. If the trial is to be fair, Senators must insist that Mr. Bolton be called as a witness, and provide his notes and other documents."

Republicans were given an opportunity to support calling witnesses on the first night of the trial. Every Republican voted to block it.