It's not a suggestion, it's a long-standing principle which is supposed to prevent bad actors from interfering with the functions of the president using trumped-up (te-he-he) charges. It's a surprise to nobody but the Democrats. There are specific circumstances in which the president could be indicted - long story short he would have to be removed from his function first, which isn't going to happen.Difference is that Jimmy Carter had more experience than "peanut farmer" under his belt by the time he was elected president. He also certainly wasn't born to wealthy elitists who bought his way to the top for him.
I find it rich discussing "giving the middle finger to monarchy" during a time at which the AG and president are suggesting the office gives him king-like immunity from prosecution.