The lack of American pride right now is due to partisanship. Look at how our politicians behave, it's like a bunch of idiot kids on a playground sometimes. Even worse, that partisanship has drifted into society in the form of biased News stations and online propaganda. That has basically turned our own country against itself. Our leaders do not even make a lazy attempt to unite the country, they just play directly to their base and say damn the rest.
A military parade does not fix that, or even begin to address it. Half the country will think it's dumb, half will have fun for a few hours, and then we'll be back exactly where we started.
Like I said, make it part of Veterans Day. I really think that is the dignified way to do this, if he really wants it to be done. Put the focus on celebrating Veterans, not showcasing our tanks. Have living veterans from every modern American war, have some fly overs, run some modern and vintage military equipment in the parade, etc. I really think that would go over well.