Of course in order to decide whether or not to impeach, Senators needs to hear from these witnesses.
But Pelosi made this problem for herself. She could have utilized the House subpoena powers to compel these fact witnesses to appear before her chamber, where she makes the rules. She could have allowed the executive privilege claim to be tested in the courts. Instead, she rushed the vote on an artificial timeline “before Christmas,” twisting the arms of members in purple districts and alienating moderate Democrats in the process. There are 30 odd freshmen Democrats who were elected in 2018 in districts Trump carried in 2016. Now they’re getting shouted down at townhalls over their impeachment vote.
All this Pelosi did because she said Trump is a threat to democracy and he is a threat to national security.
Yet if she believes that, how can she now sit on the very same articles until the Senate agrees to do things her way? Suddenly there is no urgency to impeachment.