Republicans fear "floodgates" if John Bolton testifies in Trump impeachment trial

There may be enough new pressure on Senate Republicans to allow witnesses at President Trump's impeachment trial, after the leak from a forthcoming book by former national security adviser John Bolton that contradicts what the White House has been telling the country.

What happened: Bolton alleges in his book — "The Room Where It Happened," out March 17 — that Trump explicitly told him "he wanted to continue freezing $391 million in security assistance to Ukraine until officials there helped with investigations into Democrats including the Bidens," the N.Y. Times reported.