Lies that uphold the popular ideology are harder to fight than the uncomfortable truth, and I expect Templeton's lie will stand until it is too late and the Alt Right takes over America.
Why do you think they will take over America?
There are so many factors at play that it seems at least unwarranted to conclude that being right about a few scientific matters - which do not make their proposed policies good at all - will allow them to take over America. For example, at this moment, Clinton is more likely to win than Trump. It's not a certain outcome, but it is the most likely one. Also, Democrats have a shot at getting control of the Senate. If they get to appoint one or two SCOTUS justices, that's likely to have a long-lasting influence on the country, and for better or worse overall, an influence against that of the alt-right.
Yes, granted, Republicans might filibuster everything and block her, but if they do so, they're likely to get filibustered in the future as well - not to mention Democrats might want to appoint Justices regardless of filibusters, if Republicans are adamant.
Moreover, there is resistance to the alt-right among other flavors of conservatives, not to mention the opposition of major Christian denominations.
There is also the issue of demographics. As long as people of recent Latin American descent keep growing as a percentage of the population (if not due to immigration + reproduction anymore, due to faster reproduction alone), and so do people of recent Chinese descent, that's likely to work against the alt-right. If it looks like the alt-right is gaining ground (to the point of getting a President), more and more people in groups such as those will be inclined to register and vote against them. The same goes for people of recent African descent.
There are plenty of other factors (e.g., movies, TV, etc.), and while none of them is decisive, it seems to me the evidence at this point is far too weak to warrant the conclusion that they will take over America (I'd say they probably will not, even if they become more powerful than they are today).