Rovian politics is based in BS.
The children of illegal immigrants are the Democratic Party's most reliable voting bloc. Even more reliable than blacks. But the grandchildren (if they're not thoroughly indoctrinated by left-wing Educrats), and the generations that follow, tend to vote Republican. So the Democrats have sown the seeds of their own destruction.
Also, Cuban-Americans (almost entirely living in Florida, although Ted Cruz is a Cuban-American) are VERY Republican. Their family histories teach them that socialism kills, and that any political party that accommodates socialism is no bueno.
In Texas, Greg Abbott (R) won the gubernatorial race with a plurality of the Latino vote, including a slim majority (50-49) of Latino men. Unfortunately, Puerto Ricans (many of whom live in New York and Florida), as well as California Latinos ("thoroughly indoctrinated by left-wing Educrats") are overwhelmingly leftist. But if we can duplicate the Texas exxperience nationwide, the Democrats are finished.