The moment he officially entered the Republican presidential race, and through the first debate, Donald Trump began to influence (or cheapen, if you prefer) the antics and rhetoric of other candidates.

This wasn’t new or unexpected in presidential politics, let alone Republican presidential politics. But the specter of someone like Trump driving the dynamic—as opposed to a more polished or pragmatic candidate—terrified Republican elites for obvious reasons. Many of them were hoping that 2016 would be the year that Republicans managed to avoid the worst-foot-forward problems that hobbled their nominees in 2008 and 2012, yet here was the GOP frontrunner calling Mexican immigrants rapists, another contender comparing nuclear diplomacy with Nazism, and still another one cooking bacon on the tip of a semi-automatic rifle.

The problem persists to this day, thanks to Trump’s persistent polling advantage and command of the media. But it just got meaningfully worse and now threatens to deteriorate into an outright catastrophe. For the first time since he joined the race several weeks ago, Trump has laid out a comprehensive policy approach—perhaps the most nativist, antagonistic, right wing immigration plan any leading Republican has ever proposed—and it’s earning rave reviews and approving nods from conservatives and other candidates.

Trump isn’t just shaping Republican rhetoric and antics anymore. He’s starting to shape Republican policy as well.

By design, the primary campaign is putting rightward pressure on everyone, forcing viable candidates to stake out positions they’ll ultimately regret, even in realms where Trump isn’t much of a player. At the first debate, both Governor Scott Walker and Senator Marco Rubio claimed to favor abortion bans without rape, incest, and life-of-mother exceptions. But Trump’s foray into policy will make him a standard-bearer in realms like economic and foreign policy, where he has thus far skated by on trash talk and empty sloganeering.

On Monday, Walker said his own immigration ideas are “very similar” to Trump’s—both want a wall built along the U.S.-Mexico border—and his campaign promised, like Trump, to “end the birthright citizenship problem.”

Birthright citizenship is a longstanding right wing bugaboo. It emerged briefly at the zenith of the Tea Party movement, when several leading Republican members of Congress proposed examining remedies to the Constitution’s broad citizenship guarantee. In 2011, Senator Rand Paul proposed amending the constitution “so that a person born in the United States to illegal aliens does not automatically gain citizenship unless at least one parent is a legal citizen, legal immigrant, active member of the Armed Forces or a naturalized legal citizen.”

Neither Walker, nor Trump, has specified how they’d achieve their goals. Trump’s white paper is more consistent with support for a constitutional amendment, while Walker’s comment is more consistent with support for ramping up enforcement so dramatically that unauthorized immigrants are deported before they can give birth. But the details are almost beside the larger point, that as cruel and damaging as the immigration debate was during the last Republican primary, it has become more so this time around. After they lost in 2012, Republicans set about to neutralize immigration as a campaign issue, by moving quickly to the left and helping Democrats update immigration policy for a generation. Instead they have moved significantly to the right.

That reflects a broader, more troubling trend. Three years ago, the GOP recognized the need to move in a subtly but meaningfully different direction. What they’re finding instead is that their coalition lacks the cultural and ideological space to nurture that kind of moderating impulse. Now, as on immigration, Republicans have moved right on a host of other issues, from abortion rights to voting rights. This massive strategic failure by the party apparatus has been investigated at length, and the party’s inability to prevent the 2016 primary from degenerating into another 2012-like fiasco will become the focal point of a thousand postmortems if Republicans lose the presidency again. Their mistake would be to blame it all on Trump, a GOP tourist. The problem runs so much deeper.