The Senate has voted to move forward with the impeachment trial of President Trump without hearing from additional witnesses. Next, the Republican-controlled chamber will move to acquit, leaving many unanswered questions in its wake.

Many conservatives, my colleagues included, argued the Senate should have invited former national security adviser John Bolton to testify. The choice seemed obvious: Bolton was willing to appear before the Senate, and reports about his unreleased memoir suggested he could provide valuable information that we do not already have. The majority of the public agreed that Bolton’s testimony would be worthwhile, and, in any event, whatever information Bolton has is likely to come out.