Yesterday Nancy LeTourneau pointed to a comprehensive analysis by Ron Brownstein pretty much definitively proving a hypothesis I’ve been promoting since Donald Trump’s rise to the front-running Republican presidential position this summer: in state after state, Trump’s strongest showing is among non-college educated white voters, a.k.a. the white working class.

There’s fresh evidence of this reality in the new ABC/WaPo national survey released today, in which Trump is at 46% among Republicans with no college education.

Behind these numbers is a reality that should strike fear into the hearts of Republican Establishment folk: Trump’s success with white working class voters reflects their estrangement from orthodox Republican economic policies in a way that is potentially exploitable by a third-party candidacy or (if they are very smart about it) even Democrats.

That’s the main thrust of my new TPMCafe column. Playing off Jim Webb’s hints that he may run as an independent next year, I argue that if there’s any promising turf for an indie run, it’s among white working class voters, not the largely legendary centrist “swing voters” who support the mix of conservative economic and fiscal policies and liberal social policies Beltway elites tend to think of as the higher bipartisan wisdom.

For all his highly self-conscious embodiment of the Scots-Irish Appalachian folk and their virtues and prejudices, Jim Webb has not actually demonstrated any distinctive appeal to white working class voters. Donald Trump has, in polls at least, and that makes him a real threat to the GOP if he decides he’s being treated “unfairly” and breaks his pledge to support the GOP nominee. That’s assuming, of course, he’s not himself the GOP nominee, which is no longer a completely safe assumption.

In any event, downscale white voters are clearly a demographic group that is not very firmly attached to either party. Given the ever-increasing GOP dependence on these votes–Mitt Romney got 61% in 2012 and still lost–that should be a source of real concern to Republicans who may have to defer their dreams of “entitlement reform” and high-end tax cuts if they want to hang onto their current electoral base.

Ed Kilgore

Ed Kilgore is a political columnist for New York and managing editor at the Democratic Strategist website. He was a contributing writer at the Washington Monthly from January 2012 until November 2015, and was the principal contributor to the Political Animal blog.