Pat McAfee is standing firmly by his decision to put Donald Trump on his show ... pointing out he's the freakin' President of the United States of America -- and it's Veterans Day!!!
POTUS phoned in to chop it up about sports and politics on the ESPN show on Tuesday as part of the federal holiday celebration honoring the U.S. military ... and some of his viewers weren't thrilled.
One fan even said, "Worst president we’ve ever had. Sad PM allows this trash on his show.