One of the media’s most persistent shortcomings during this election season has been an unwillingness to recognize the issue central to Donald Trump’s success. Post-game analyses offer many explanations—that Republicans are stupid, that they’re nihilistic, that the media failed—yet many barely mention the real reason: immigration. It’s an omission so persistent that the blogger Mickey Kaus, an immigration hawk, has jokingly begun to award omertà prizes in its honor. Failing to understand its salience with Republican voters has been central to failing to predict who would rise and who would fall in this primary season.

Now that we head toward the general election, of course, the issue of immigration, which was gold for Trump in the primaries, is widely seen as his kryptonite. But it may be that the exact opposite is true: that immigration is the issue that insidiously defeats Hillary Clinton.

By most appearances, Hillary is in good shape for November. She has a grasp of policy and familiarity with the ship of state that will create a startling contrast with her opponent in their debates. Trump has a long way to go in fund-raising. His lack of impulse control shows few signs of being remedied. The list goes on for longer than any of us has time to complete. Still, Clinton’s fight in the primaries has caused her to take some positions that she’d prefer to avoid in the general election, and those on immigration may be costliest.

Everyone knows that Trump has staked out extreme turf on border control, promising a wall and a deportation force. But Clinton has gone far in the opposite direction. “I would not deport children,” she said at a debate in March, after proposing the exact opposite in late 2014. “I do not want to deport family members, either.” In short, under Clinton’s policy, if you manage to sneak across the border illegally and make it into a city, you won’t be removed. You could call that open borders, except it’s messier. It’s more like a free-for-all.

The question, then, is who is less in sync with the mainstream. Most immigration polls are unreliable, offering choices between fantastical extremes—between mass deportation (which won’t happen), for example, or legalization once the border has been controlled (which is like drug legalization once addiction has been eliminated)—or leaving terms so vague as to be nearly useless. A Politico poll from 2014 found that more than 70 percent of Americans, including 64 percent of Republicans, backed “comprehensive immigration reform”—but it never defined what the terms of the “reform” might be.

Still, here is some of what we have to go by. At regular intervals, an organization called the Public Religion Research Institute offers polls showing that more than 60 percent of Americans favor a path to citizenship for immigrants who are here illegally, provided they meet certain undefined requirements. This suggests that amnesty, at least in theory, is acceptable to most Americans. At the same time, support for border control is strong. A Washington Post/ABC News poll from April 2013 found that 67 percent of Americans supported spending more on border enforcement, and 83 percent supported laws requiring businesses to check on the immigration status of prospective employees, a measure that many Democrats have opposed. It also found that, while 62 percent of registered voters prefer to grant unauthorized immigrants a path to citizenship (provided they meet “other” unspecified requirements), 50 percent (versus 44 percent) would favor it “only after border control has been improved.”