But the midterm elections saw a significant shift. The Democrats captured two traditionally Republican, suburban seats in the House of Representatives, and Democrat Beto O’Rourke, now a presidential candidate, came within 2.6 points of ousting Republican Sen. Ted Cruz. Recent polling suggests Trump could be vulnerable in the state in 2020, a product of continued resistance in the suburbs of Austin, Dallas, and Houston.

Some Republicans have attributed the outcome last fall, in which the GOP also suffered losses in state legislative races, to Cruz’s unpopularity and the resources invested by O’Rourke and his allies, a feat Democrats are unlikely to repeat in a national presidential contest. Senior Republican strategists in Texas are warning against that line of thinking.

“Everybody thinks it was a Cruz-Beto thing. But it’s a mess,” a GOP adviser said, requesting anonymity in order to speak candidly. “Independents are behaving like Democrats — like they did in 2018.”