Trump's impeachment 'has to happen'

Biden made the comment during a brief one-on-one interview with CNN in the halls of the West Wing. He acknowledged the effect it could have on his legislative agenda and Cabinet nominees but said there would be "a worse effect if it didn't happen."

Biden told CNN he believed the outcome would be different if Trump had six months left in his term, but said he doesn't think 17 Republican senators will vote to convict Trump.

"The Senate has changed since I was there, but it hasn't changed that much," Biden said.

His comments came the same night the House impeachment managers formally triggered the start of Trump's second impeachment trial after they walked across the Capitol and began reading on the Senate floor the charge against Trump, the first president in history to be impeached twice.