It's been clear since 1989 that flag desecration laws are unconstitutional.
First Amendment Library - Case
Maddie, Maddie, Maddie. Flag desecration is just another exercise in total disrespect for one's country and rebellion against it. It was a very highly visible exercise back in the '60s-'70s. There shouldn't have to be a Constitutional argument about it at all, but if it has to be a question of Constitutionality I would suggest it be defined as a felony. People should have enough good character, respect, concern and gratitude for their country, the people over the decades who came here and helped make it great, and those who have stood up and protected it and the freedoms we have because of them.
Unfortunately, today, no one is very much concerned with respect for anything or anyone, gratitude for anything, self-respect, responsibility, actions and consequences, or anything else. There's an excuse or newly-discovered "syndrome" for everything. And the more we tilt in that direction, the more banal we become and the more we applaud ourselves for achieving yet another low ... yet, we're never happy, are we? It's never enough, we keep looking for the ever-illusive thing that's going to give us the next high on our road to self-destruction.