These findings emerge from a cumulative analysis of 605,172 interviews SurveyMonkey conducted with Americans in 2017 about Trump’s job performance. At my request, Mark Blumenthal, SurveyMonkey’s head of election polling, calculated Trump’s average approval rating over the last year among groups of voters segmented simultaneously by their race, gender, education level, and age. That extra level of detail, not available in conventional polls because their samples are too small, offers a more precise picture of Trump’s coalition.

The SurveyMonkey results put Trump’s total approval rating for 2017 at 42 percent, with 56 percent disapproving. That’s slightly higher than, but within range of, other major public surveys.

In the 2016 election, exit polls found that Trump’s best group was whites without a four-year college degree; he carried 66 percent of them. But his approval among them in the 2017 SurveyMonkey average slipped to 56 percent. In 2016, whites with at least a four-year college degree gave Trump 48 percent of their votes. But in the 2017 average, just 40 percent approved of Trump’s performance, while a resounding 60 percent disapproved.

Layering in gender and age underscores voters’ retreat. Trump in 2016 narrowly won younger whites. But he now faces crushing disapproval ratings ranging from 62 percent to 76 percent among three big groups of white Millennials: women with and without a college degree, and men with a degree. Even among white Millennial men without a degree, his most natural supporters, Trump only scores a 49-49 split.

Trump’s support rapidly rises among blue-collar white men older than 35 and spikes past two-thirds for those above 50. But his position has deteriorated among white women without a college degree. Last year he carried 61 percent of them. But in the new SurveyMonkey average, they split evenly, with 49 percent approval and 49 percent disapproval. His approval rating among non-college-educated white women never rises above 54 percent in any age group, even those older than 50. From February through December, Trump’s approval rating fell more with middle-aged blue-collar white women than any other group.

Trump’s position has also eroded since 2016 among college-educated white women. In 2016, those white-collar voters preferred Hillary Clinton over Trump but gave her only 51 percent of their votes. Now, in the 2017 average, 66 percent of them disapproved of Trump and 58 percent strongly disapproved. In every age cohort, at least three-fifths of them disapproved.

Trump did better among college-educated white men, usually a reliably Republican group. But after those men gave him 53 percent of their 2016 votes, an equal number said they disapproved of his performance in the yearly average. Trump’s approval rating is net negative not only among college-educated white Millennial men, but also those ages 35 to 49; he only pokes his head above water—and just slightly—with those 50 and older.