If those numbers are correct the GOP will need to start making real efforts with minorities within the next 5 years. Those numbers aren't sustainable long term.
Even if we just assumed that all constituencies remained static and old whites are being replaced by less conservative whites... that would be enough to cause the GOP problems... then you factor in the notion that the minority population is growing and it becomes implausible to continue this.
As others have stated, young whites are almost exclusively neo-Nazi/alt-right. The country will be voting like Mississippi and Alabama in 50 years.
As I've said several times, the "almost exclusively" was hyperbole. Anyway, as for whites in general, Wolverine22 said something similar yesterday:
No and this is why I say that Trumpism will continue long after Trump. As whites lose the numerical majority, even Bernie supporters will become increasingly reactionary conservative/racist and embrace cynical, white nationalist politics when that brand of Trumpism fits their fears. This is why unless we see a California-like surge in non-white voters over a decade, I don’t see demographic change turning America into California. Whites will just vote more and more Republican and the GOP will be able to win elections by winning 97% of the white vote while tanking even further with minorities.
