What we witnessed on February 13, 2021 with Mitch McConnell’s reason for voting not guilty in the impeachment trial of ex-president Donald Trump, is the Senate playing the Judicial Branch.
The question on whether the Senate had jurisdiction to hold impeachment trial was raised, and voted on. The Senate’s vote was that it had jurisdiction.
In a regular court of law, once a judge has ruled, the issue can no longer be argued, and jurors are instructed not to consider the issue during deliberations. However, the Senate is not a court of law. Mitch McConnell disregarded the majority Senate vote and used the issue of constitutional jurisdiction to acquit ex-President Donald J. Trump.