While I mostly agree that the Trumpian right in a type/form of Caesarism is a threat to our system (I disagree as to how much of one they are - Trump as Caesar? - but they most certainly are) it would be helpful Mr. Biden if you had told your party to stop helping MAGA candidates in primaries by opposing their non-MAGA opponents. If you really think they're a threat then stop playing politics with them in the hopes of getting more of your candidates elected by helping the less electable MAGA candidate win. I don't think it's an accident, maybe it is, that you waited until after many of these primaries were finished to give this speech.
And, frankly, using the Marines as a backdrop was uncalled for. Not to mention that we're not in this divisive period solely because MAGA Republicans have been acting horribly. A little criticism of the President's side would have helped. That's not "whataboutism"; that's the truth.
As Lincoln said during a much more serious crisis, "We are not enemies, but friends. We must not be enemies." A little more Lincoln would be welcome.