Actually the largest margin in the history US Senate Impeachment Trial the Senate found Trump guilty. But under the rules of Impeachment Trials it was not sufficient for conviction. But this was the largest cross party vote to convict in all of US impeachment history.
Several of those GOP senators who voted not guilty then went on to say that Trump very obviously and definitely is responsible for the insurrectionist attack on the Capitol. Eg, McConnell, "no question about it."
They know full well that he's guilty, but they chose to hide behind the cowardly lie that they didn't have jurisdiction because he's no longer in office. That lie was disproven on the very first day before the trial actually started.