So... your heatmap has a lot of red in the south, which to me says that diversity has increased and republican voting has increased. However, it has a lot of blue in, say, New Mexico. is this saying diversity has decreased and republican voting has decreased? Or is it saying diversity has increased and republican voting has decreased? Because I think it says the latter (greater diversity, less Republican voting). But what I can look up - in 2000, NM was 66% white while in 2010 it was 68% white - says the former.
It's the former. For clarity, I've made a map for each phenomenon: NM has become less diverse and has moved to the left. (Note: I've defined diversity as 'not being white'.) If you were to make the argument that more diversity led to a reactionary vote for Trump, the collorary (less diversity means less movement to the right) is also important, so both blue and red parts of the hotspot map support that argument. However, this is only correlation and not causation. 
