And the mass of replies that each of his tweets garners, most of which I would personally consider to be unilaterally "hateful", especially the ones that seem to always float to the top...
They have already responded to this, the rules are applied with some leeway to account for "newsworthiness". The president's tweets will not be taken down and his account won't be banned because of a blind application of the rules.
If Twitter starts censoring mainstream political speech by even the POTUS, I think that'd draw more attention than they want.
Right now and in the future they can censor people that few people care about and probably have a much bigger impact without any outrage outside of niche communities.
My understanding is that the military and police, as representatives of an elected government, are legally allowed violence and should also be allowed to exist on Twitter.
They aren't affected by Twitter's existing rules, and presumably won't be by any new rules, unless they are changing not only the written rules but the unwritten rules controlling whether or not they apply the written rules.