It’s a matter of perspective.
From your, and many rational being’s perspective, there being a felon for president is a bad thing. You trust the judicial system, you think they found and convicted rightly, so now we have a bad man in charge.
From the other perspective, the majority voting perspective, the judicial system has been usurped and politically weaponized, the trial was a sham and the conviction false. He’s not a felon, just an unjustly labeled political martyr. Or maybe even a felon is better than a woman, or, gasp, a colored woman! The racism and misogyny never died, just sat in the back until it was allowed to speak again.
Why do they think this? Well, why do you think opposite? Different upbringing, education, social media exposure, less lead in you/your parents?
Trouble is, would you consider someone best if they have imperialist values? Socialist ones? Would they require a Ph.D? And no matter what you answer, someone will believe the opposite. Who gets to pick the best of the best? In the current system, supposedly the common people do.
And they picked Felump.
Sure, stats say he wasn’t actually super popular, but the voters that could have gone another way made their vote too by leaving the box empty and giving him no opposition. To paraphrase Rush, “if you choose not to decide, you still have made a choice”. So whether by checking the box or not, the people spoke, and here we are.