I really am okay with this. That means republicans are a dying breed.
That makes the INCREDIBLY idiotic assumption that the political landscape stays exactly the same for the next 50-60 years (the length of time that you are going to need to make whites a 'non-majority'). Further, even the premise that whites are going to be the minority after that time requires another idiotic assumption that the rate of change is going to stay rather constant. BOTH of those assertions are asinine. As the demographics shift, so to will the political parties, socio-economic status and the rates of change that you see in population demographics.
Only an idiot thinks that more of one group = more votes for their particular stripe of political party half a century later. Look back 60 years and ask yourself if the parties resembled what they are today? Oh wait - that is around the time that Jim Crow laws were all the rage around then. Remind us WHO passed those again?