https://www.breitbart.com/politics/2020/01/22/hans-von-spakovsky-senate-procedure-had-to-cure-house-evidentiary-defects/
From article a change noted from Clinton Impeachment.
As Spakovsky explained:
Virtually the only difference between the Clinton resolution and the McConnell resolution was one change that was actually necessitated by the Democrats. Look, in the Clinton resolution, it simply said that all the evidence that was developed by the House will be admitted into evidence in the Senate. The McConnell resolution also said all of the evidence developed by the House will be admitted into the Senate, but subject to objection by the president’s defense team based on allegations of, you know, hearsay or anything like that. Now, why did they put that in? Well, because during the Clinton investigation, representatives of both parties were given the full ability to question witnesses, to call any witnesses either side thought was important. But yet what did Democrats do in this impeachment investigation? They — Democrats restricted the ability of Republicans to cross-examining witnesses, they prevented them from calling witnesses they thought had relevant information. So the only change in the resolution that was approved was required because of the way the Democrats unfairly changed the rules in the House.