Sen. Mitt Romney indicated Saturday that he is "likely" to vote to call witnesses in Trump's impeachment trial, but would not commit to doing so just yet. "I think it's very likely I'll be in favor of witnesses but I haven’t made a decision finally yet and I won't until" arguments on both sides are done, Romney told reporters. Steve Kornacki breaks down the number of Republicans who could potentially vote for witnesses and evidence in the Trump impeachment trial.