As the presidential election enters its final three months there are plenty of indications that one of the presidential tickets is doing everything it can to limit its ceiling with voters. Even before the Republican National Convention, the mathematical wisdom suggested that Donald Trump was going to need a surge in support from whites to challenge Hillary Clinton in November. But that demographic is at low tide for the Republicans. After a tumultuous couple of weeks that included a laundry list of high-profile errors, the Trump coalition appears to be retracting.

In the latest Fox News poll, Trump is leading white registered voters by 10 points, 49 percent to 39 percent. A new McClatchy survey recorded an even slimmer margin, 41 percent to 39 percent for Trump. He leads white non-college graduates by about 15 points in both studies.

These margins, while fluid, don’t even rise to the point of being damaging to the Trump campaign. They wreck the entire ship. According to exit polling, Mitt Romney won whites by 20 points, with 59 percent total. A different model, this one from the New York Times, estimated that Romney won the group by 17 points. Anything less than the same share for Trump, and they may as well not hold a single debate.

Republican strategists told the Hill that the GOP nominee needs between 63 and 68 percent of the white vote to win the election. And FiveThirtyEight estimated that Trump would need to win whites by at least 22 points—a bare minimum, assuming that the electorate's demographics don't change from 2012 to 2016. Because the share of white voters is expected to decrease, however, continuing the country's shift to a more diverse pool of voters, Trump will likely need to do even better.

As such, he needs to give the public a reason to come to his camp. He's not doing it. Take these tough figures from the Fox survey: Only 43 percent of respondents say Trump is qualified to be president, 40 percent say he has the requisite knowledge, and just 37 percent say he has the proper temperament to do the job. Group these stats with the general pattern of Trump's high unfavorable ratings, and there's little to suggest that Trump is making himself a more attractive candidate to the public.

The primary has been over for a while now. Whereas the Republican nominee managed to endear himself then to a sufficiently significant—and utterly committed—base, there are now tens of millions of additional voters up for grabs. They include Democrats he'd be inclined to pick off with his trade and infrastructure rhetoric. They include independents. And they include the Republicans who didn't vote for him between February and June. Since the convention, he hasn't conveyed a message to attract any of them, white or otherwise. He has continued to be the story—which continues to be his problem.