Seven months into his presidency, Donald Trump is deeply unpopular. In Gallup’s latest poll of presidential job approval, he’s down to 34 percent, a level unseen by most presidents outside of an economic disaster or foreign policy blunder. In FiveThirtyEight’s adjusted average of all approval polling, he stands at 37 percent. And yet, few Republican lawmakers of consequence are willing to buck him or his agenda, in large part because their voters still support the president by huge margins. What we have clearer evidence of now is why. From polling and the behavior of individual politicians, it’s become harder to deny that people support the president not just for being president, but for his core message of white resentment and grievance—the only area where he has been consistent and unyielding.

You see broad Republican allegiance to Trump in the polling. Nearly 70 percent of Republicans say they agree with Trump on the issues. And 78 percent of Republicans say they approve of the president’s overall job performance. Republicans who have bucked or criticized Trump, like Sen. Jeff Flake of Arizona, have jeopardized their political futures as a result.

You also see the degree to which white racial resentment is a key force among Republican voters. Most Republicans, remember, agreed with President Trump’s response to the violence in Charlottesville, Virginia, where he held both sides—white supremacists and counterdemonstrators—responsible for the chaos that claimed the life of one anti-racist protester. In an analysis of recent polling, my colleague William Saletan observes that, across a number of questions gauging racial animus, Republicans generally (and Trump supporters specifically) are most likely to give answers signaling tolerance for racism and racist ideas. Forty-one percent of Republicans, for example, say that whites face more discrimination than blacks and other nonwhite groups (among strong Trump supporters, it’s 45 percent). Ten percent of Republicans and 19 percent of strong Trump supporters have a favorable impression of white nationalists, while 13 percent of the former (and 17 percent of the latter) say it’s “acceptable” to hold white supremacist views.

And, importantly, you see these ideas expressed not just in polls but on the ground, as well. In 2014, Ed Gillespie ran for Senate as a Virginia Republican in the mold of figures like John Warner and Bob McDonnell—conservative but not a bomb-thrower. The kind of Republican politician who could make ground in Northern Virginia and other Democratic-leaning parts of the state. Gillespie tried to run that campaign in this year’s Republican primary for governor, and he might have won without trouble if not for the presence of Corey Stewart, an otherwise obscure county official who backed Donald Trump in the 2016 presidential election and challenged Gillespie as a Trump-like figure. Vocally standing in defense of the state’s Confederate monuments, Stewart ran as the candidate of white anger and racial resentment, and he almost won, losing by fewer than 5,000 votes.

Gillespie learned his lesson. In an August ad against his Democratic opponent Ralph Northam, he blasts “sanctuary cities.” In the past month, he’s hired a former Trump campaign aide—Jack Morgan, infamous for his warning that the country is on the brink of a second civil war—and has pledged to defend Confederate statues from local efforts to remove them. Donald Trump may have lost Virginia to Hillary Clinton, but Virginia Republicans are committed to the president and expect the same from their candidates.

It’s true that it’s rare for a president to lose anything more than a small minority of his partisan base. But Gillespie’s recent turn shows there is more than simple partisanship at play. There’s nothing about partisanship that forces a figure like Gillespie to go beyond simple Trump support to embracing the most inflammatory, racially reactionary parts of his appeal. In theory, it should be possible to maintain allegiance to Trump without pantomiming the resentment that fuels his presidency.

But this isn’t true in practice. Signaling allegiance to Trump requires embracing white identity politics, because those beliefs reflect the views of many Republican voters.

White identity politics have always been dominant in American life, one of the key forces that shape much of the nation’s political and social landscape. It’s not that Trump is new; it’s that he’s explicit, and in making his open appeal to white identity and its supposed endangerment, he has raised its salience. Before Trump, white resentment was part of Republican politics. In the age of Trump, it increasingly defines it.