I really can’t understand why any GOP Senator would want to prolong this for witnesses, considering that the verdict is certain to remain unchanged. A vote for witnesses is basically a vote to waste a month of the Senate’s time, and give the Democrats and the media another month of unimpeded Trump bashing. And they’re going to do that, regardless of what happens in the Senate.
Some Senators like Romney are out for the spotlight and to make Trump squirm. Some like Collins are in tight races for reelection and some like Murkowski are are just butt azzed stupid.
Because (1) they are in a bluish state or (2) are jealous they lost election to a community organizer from Chicago while a non-politician who never ran for any election before defeated the sure to win first female president candidate handily, or (3) they are so country-club type personalities, they can not stand a president who is never shy in counter punching attacks immediately.