The margin of error on that is fairly big, of course, since it's a subset of a normal poll sample. But looking at polls from CNN/ORC and Fox News over time, the pattern is consistent: Trump gets much more support from those without a college degree than those with one, though the degree of that lead wavers. (We first highlighted this in the earliest days of the Trump surge.)
But it seems likely that the gap is growing.
We can look at this as a microcosm of the 2016 election on the whole. Trump has consolidated a base of support; the establishment is fractured in its support for someone to stand up to him. This isn't a clean analogy, but it maps loosely. More than 40 percent of those without a degree in the CNN/ORC poll back Trump. Those with a degree can't make up their minds.
If that holds, or if Trump's grip on those without a degree strengthens, it's not good news for those hoping he's not the nominee. In 2012, turnout by those with or without a degree varied by state. In Iowa, 52 percent of Republican caucus-goers had college degrees, according to exit polling; in South Carolina, 47 percent did. The average across 20 states was about half-and-half. Thirteen states, though, had more people without college degrees turn out to vote than those with a degree.
In other words, a lot of people likely to vote in the primary are people who are likely to strongly back Trump.
That support could help Trump in a general election, too. Slightly more than half of those who voted in 2012 didn't have a college degree or had an associates degree. They supported Barack Obama more than Mitt Romney at margins inversely proportional to level of education. But even now, Trump does much better in head-to-head match-ups against Hillary Clinton among those without a degree.
There's a lot of fluctuation in those margins of support for Trump among voters without a degree. This new CNN/ORC poll could be something of an outlier, over-representing the strength of that group (and therefore inflating Trump's overall support).
Or maybe Trump is locking up that not-small base of support. If so, his nomination becomes much more likely -- if not his election.