There is something to that sentiment.
As I said, it will take a while for State politics (Texas R's do well, especially with Hispanic last names), taking special account for the re-districting attempting to thwart their rise. Don't let Rove's abstract on local politicians and statewide races distract from the discussion on the General Election.
In National Elections, the decline is steep and while the population increases, the decline has a larger impact on the State's Electoral College:
2000: Bush 49%
2004: Bush 49%
(2006 Immigration debate truly started)
2008: McCain 35%
2012: Romney 29%
Population of Voting Age Hispanics:
2012: 4.2m
2016: 4.8m (and 33% are 18-25, while 60% of eligible whites are 45 or older)
Democrats need to focus on one thing - turnout. Republicans have a number of things to fix = we saw this in CA in 1994 after Prop 187, effectively turning the state into a Supermajortiy Dem state with bad policy targeting Hispanics.
