WASHINGTON—A brewing fight over whether to call John Bolton as a witness in the Senate impeachment trial of President Trump could plunge Congress and the White House into uncharted territory, with almost no precedent to guide whether a senior government official can be muzzled in a trial of his former boss. The revelation that Mr. Bolton has written and circulated the manuscript of a book addressing key matters at issue in the impeachment trial has increased scrutiny on whether the Senate will call Mr. Trump’s former national...

Source: Wall Street Journal January 27, 2020 20:37 UTC