The running joke in GOP circles is that Trump should build a wall along the northern border in Texas to keep the liberals out.

Republicans argue that conservative policies led to the economic conditions that have been a magnet for job-seekers and employers, and they believe that many people moving to the state will be receptive to that message.

But they also acknowledge that domestic migration has hastened the state’s political realignment, particularly in the fast-growing metro areas that account for more than two-thirds of the state’s voting population.

“The suburban counties just cannot be taken for granted,” said Bill Miller, a GOP lobbyist and consultant in Texas. “Republicans took them for granted in the past election and paid a steep price for that. The reason Texas is not more purple is that rural Texas is still staunchly Republican. But the suburbs have changed and so many of these races are just not a lock cinch for Republicans anymore.”