It was never going to work. I am conflicted over whether it was the right thing to do - Trump is an awful person who is unfit to be president again, but from a cold, legal and technical point of view, I couldn't vote to convict him based on the facts presented by the Democrats.
Leaving aside the question of whether it was constitutionally correct - which I'm not comfortable it was - the prosecution argument relied on emotion rather than hard evidence. And at one moment they claimed the riot wouldn't have happened if Trump hadn't incited it, at another moment they reported that a protester left home in the morning telling his children he might not be home - implying he was expecting there to be trouble.
From a purely legal point of view, the case was not proved beyond reasonable doubt. I also dislike how rushed it was - the Democrats naturally wanted to rush the trial so they can get on with business, but the impeachment of a president and barring them from future office is the most important business of all.
Add to that the voting patterns - all Democrats and nearly all Republicans voting on party lines - means that acquittal was the only option. In a real trial, one expects unanimity from the jury. The judge might allow one or two dissenters and a majority verdict, but doesn't have to. The trial smacked of being a show trial.