Momentum is growing to call witnesses to Donald Trump’s impeachment trial after it was revealed his former national security advisor has written a book manuscript saying Trump directly tied military aid to Ukraine to politically-motivated investigations.

The revelations about John Bolton’s forthcoming book have shaken up the Senate impeachment trial, which appeared to be moving toward a speedy acquittal for Trump as early as the end of the week.

via ‘This is a game-changer’: John Bolton revelations upend Trump’s impeachment trial