Majority of Americans support assault weapons ban....

[Okay, maybe Mike Johnson is a competent parliamentarian.]

Any rifle that fires more than one bullet each time the trigger is pulled is illegal.

I don't think that applies to submachine guns like Uzis though which is kind of perplexing as they have zero legit use. You can't use them to hunt and for self defense they're likely to hit bystanders and are unwieldy. Their main purpose is for drive bys. Why would any non gang member have any use for one? "Defend muh FREEDOMS against government TYRANNY" should not be a valid answer to anyone who lives in the real world.

That IS a valid reason. Indeed one look at the founding will find it to be one of the two main purposes of the Second Amendment.

The fact that a specific group of eighteenth-century intellectuals had a reason in mind doesn't automatically make the reason good. Yes, I'm aware that this is an argument for repealing or modifying the Second Amendment rather than for attempting to legislate with it still in place.

[Okay, maybe Mike Johnson is a competent parliamentarian.]

A few points:

1. The interpretation of the Second Amendment and the English common law preceding it that blackraisin is advancing strikes me as, broadly, the 'correct' one. This doesn't, however, automatically mean that advocating a new constitutional amendment to repeal or set coherent limits on the Second would be legally unacceptable or morally wrong, because
2. While a purely consequentialist view of law (or of anything, for that matter) is obviously morally unacceptable (this is one of my many problems with the 'law-and-economics' fad in legal studies), so is a completely consequence-neutral one. Not only should rights imply corollary duties, both rights and duties should imply some sort of standards of efficacy in promoting the common good and creating a just society.
3. Scaremongering about the AR-15 specifically is foolish.

Even though I have very un-libertarian Issues stances I do actually have a conceptually anti-authoritarian streak and I sympathize with the pro-gun position more than probably most leftists, either on this site or elsewhere, do, but at the same time the current American cultural and legal attitude towards guns (an attitude that is, yes, constitutionally enshrined), compared to the attitude almost literally everywhere else in the developed world, is getting ridiculous. (This isn't supposed to be a boilerplate 'muh Europe' argument; if it strikes everyone as one then I'll retract it, but the rest of what I'm saying stands.)