Here's what bugs me: what guarantees that it stays a one-time tax? What guarantees that it is only on "the largest AI companies"? What keeps it from becoming "we'll take half of anything anybody has that we don't like"?
And what keeps me from becoming part of "anybody they don't like"?
:-/
AI is nukes to be funded by the taxpayer is another intersecting take which follows from you comment. If that's the case, include them in the military budget, not in a plan sold as some kind of generous giveaway.
And should they?