At this point, we're down to conjecture. It will doubtless require higher taxes, which will quite possibly counter or outweigh any benefit of more money to spend. It's a big risk to take with the entire country.
> migration for benefits is a problem.
You don't have to have immigration controls, just establish residency requirements with a certain amount of time, holding down a job for however long, etc.
> Means testing is additional bureaucratic cost
Still doesn't make sense to send money to Jeff Bezos.