I highly doubt that. The most likely result of 20,000 people moving into the state is those 20,000 people moving back out of the state in a few years.
The possibility of 40,000 *contrarian votes* won't be much of a problem if there are 400,000 of those new chum voters overwhelming them by the end of the decade
Like I said, the only state you could take over with that many votes is Wyoming--and there are very good reasons for Wyoming having as low a population as it does, most of which relate to the free market. Increasing the population of Wyoming by 400,000 or so would require a program of public largesse--and lots of it--in order to achieve the goal.
if America still has anything resembling free or honest elections by then.
Well, it looks like you have a handy excuse for failure already primed up: "the elections were stolen by the EE-VIL Republicans and Democrats."
It's what passes for Libertarian foresight.