Let's agree to stop calling the NAU a "conspiracy," OK? Damn few "conspiracies" spell out their plans on their own web site. Rather the NAU is viewed by those whom a mysterious God hath placed above us, as the logical LONG TERM solution to a set of problems which they, in their infinite wisdom, see before us.
Our basic problem: Vigorous consumer economies depend upon a growing population base. Period. Any fool, even those employed by the government, can see we ain't got that, left to our own devices, because having children costs money and limits many fun options that are the reward of a brisk consumer economy. Not to mention, female "career" opportunities. New working young people are also required to pay the taxes that provide the benefits paid out to old people as consumer societies drift ever toward socialism.
Now, we can't get these new people we need from Europe anymore. They have the same problem. Just as we are overrun by Mexicans, they are overrun by Muslims and Africans and a combo of the two. Buchanan, despite his obvious faults, ain't told no lie. The Christian West is committing suicide.
Our leaders see us eventually overrun by our non-European Third World neighbors and simply want to get ahead of the curve ... control it before it controls us; maybe make it a "good thing," instead of a bad thing, which seems more than likely without some kind of action to integrate our new population. Their mistake?
So now, in typical government fashion, they got mayhem. And we have replaced the children we didn't have, or the children we killed, with a soon-to-be 100 million alien (to us) population. By the time the NAU comes up for a referendum, or for ratification, our leaders foresee that we will be the northernmost country in Latin America, albeit with a (hopefully) still significant "Anglo" minority. They (or whoever "they" is at that time) then will have the votes to pass it.
And the Republicans are willing to become a one party gov't (and it won't be their party) because most have been bought and paid for beyond their wildest dreams to sell out not just their constituents, but their country.