It’s already trending that way, but the second Congress passes the immigration bill, Republicans will have little or no advantage among voters. They are probably already figuring ways to maximize the vote.
Texas is more Republican than it has ever been, presidentially Obama got 41% recently (44% in 2008), that is a margin that isn't going to be made up in 4 years, but within the state government, the republicans have a great amount of recent gains.