Bush-style Republicans once ruled Texas. Now Trump’s the new sheriff.

The story of what the Republican Party once was and what it is now can be told through the Bush family of Texas, whose newest political star survived a critical test in Tuesday’s primary.

George P. Bush, 41, is the state’s land commissioner, but his pedigree suggests loftier ambitions. To make any climb, though, he must first survive his reelection race this year, and to do that he has embraced — and been embraced by — Donald Trump.

It’s a partnership rich with irony, given Trump’s relentless disparagement of Jeb Bush, George P.’s father, in 2016, but it’s more significant because it represents a surrender of sorts — by the Bushes to a political force that stands as a rebuke of their family brand.

The modern Bush dynasty took shape in Texas in the 1960s. Back then, George H.W. Bush was a political pioneer, a native-born Yankee planting a Republican flag in ancient Democratic turf. When he was elected to Congress from a Houston-area district in 1966, it marked the GOP’s first-ever victory in the 7th District, which had been around since just after Reconstruction.

It was no fluke. Bush, a senator’s son who’d made his own way in the oil business, was a comfortable match for the locals. The area was ancestrally Democratic but suburban in nature, with a sizable professional class. When Bush won in ’66, the Associated Press pointed to his “moderate conservative” platform and condemnation of the far-right John Birch Society as key selling points.

That breakthrough proved a turning point. From Bush, the seat was passed first to Bill Archer in 1970 and then in 2000 to John Culberson, who holds it today — 52 uninterrupted years of Republican representation. But in 2018, this dominance faces an existential threat: Donald Trump, whose culture war politics are rebranding the party and realigning America’s upscale suburbs.

As a candidate in 2016, Trump actually lost the 7th District by a point to Hillary Clinton. To call this an abrupt shift would be an understatement; just four years earlier, Mitt Romney carried the district by 21 points. That Romney fared so well should be no surprise. In style and ideology, he is George H.W. Bush’s direct political descendant — an impeccably credentialed, well-mannered, business-friendly internationalist.

Trump, of course, is the antithesis of all of this, and Houston’s suburban voters didn’t like it two years ago. Now, the risk for the GOP is this Trump-phobia will trickle down the ballot in the fall and, at long last, enable Democrats to reclaim the House seat that George H.W. Bush took from them all those years ago. Needless to say, the 7th District race has already emerged as one of the hottest in the nation.

And yet, there are other parts of Texas where the Trump style is a hit. The president’s approval rating with Republicans in the state stands at 83 percent, making him more popular among the party faithful than both of the state’s GOP senators, Ted Cruz and John Cornyn. It means that an ambitious Republican looking to win statewide breaks from Trump at his or her own peril.

George P. Bush seems to understand this. As the rest of his family stood back, he stepped forward two years ago to endorse Trump. And on Tuesday night, with the president publicly vouching for him, Bush beat back a Republican primary challenge for land commissioner. With the win, he will now be heavily favored to retain his seat — and keep his future prospects open — in the fall election.

It may be that in 2018 Trumpism saves the newest member of the Bush dynasty even as it snuffs out what the patriarch built.