The stupidity is the point
By 
The Trump defense team used about a quarter of their allotted time, and had their twelfth-rate lawyers deliver a combination of intelligence-insulting lies, false equivalences, wingnut buzzwords, and references to Georgia Secretary of State “Ben Roethlisberger”:
Lawyers for Donald J. Trump delivered an incendiary but brief defense of the former president on Friday, calling the House’s charge that he incited an insurrection at the Capitol a “preposterous and monstrous lie” as they falsely equated his conduct to Democrats’ own combative rhetoric.
With his second impeachment trial racing toward a conclusion, the lawyers on its fourth day channeled the former president’s own combative style and embrace of falsehoods to claim, contrary to facts, that Mr. Trump never glorified violence during his presidency and that he consistently called for peace as the rampage at the Capitol unfolded. Showing video clips of Democrats urging their supporters to “fight” and Mr. Trump venerating “law and order,” they sought to rewrite not just the narrative of his campaign to overturn the election but that of his entire presidency.
“This trial is about far more than President Trump,” said Bruce L. Castor Jr., one of the lawyers, as he closed the defense. “It is about silencing the speech the majority does not agree with. It is about canceling 75 million Trump voters and criminalizing political viewpoints.”
The “CANCELLING” argument amounts to a claim that the impeachment process outlined in the Constitution is unconstitutional.
This performance was objectively embarrassing, but why wouldn’t it be? If you’ve ever been part of a process that offered the form of due process without the reality, you’ve likely noticed that the party that holds the cards won’t even bother pretending to take the process seriously, because why would they? Having unprepared people make incredibly dumb arguments knowing that it doesn’t matter just acts to further discredit the process. And Trump’s most servile caddies are completely open about the the fix being in. (Remember when Tailgunner Ted got an enormous amount of inexplicable praise for giving an RNC speech that amounted to “don’t feel obligated to vote for Trump…unless it looks like he can win”? Good times.)