The only thing conforming to a dress code, speech code, or other creeds proves is you stand for nothing but the status quo and a conformist.
Like the office in the era of work at home, the suit is the western symbol of enslavement that includes a literal collar they call a tie. Americans have been conditioned to believe it is upscale or stands for something better.
Dress literally means nothing. Maybe he is a phony making a statement, or maybe he just wants to be comfortable. I look more at what he says he stands for and how he votes than what he wears.
The people who are concerned with this should look in the mirror and ask why. Most of those I see giving a shit about it are church fucks who are obsessed with things like dress, and language.