It’s not hard to guess what is going on with the results from this latest poll, reported by Hot Air, that shows support for a border wall dropping precipitously. It’s Trump. Sort of a “the friend of my friend is my enemy” kind of thing.

From Allahpundit at Hot Air:

Five years ago the public was evenly divided. Six months ago the public was still evenly divided. Six months later, boom — a disaster at 38/58. What changed? Why isn’t terrorism turning those numbers upside down?

This is no longer a national issue, it’s a “Trump issue,” and some voters will let their antipathy to Trump writ large dictate how they feel about particular policies on which he’s taken a strong stance.

Make no mistake, that change in fortunes for this issue is huge. It went from even to 20 points to the negative in a short period of time. Trump voters love to say “trust the people” when they are talking about electing him. Call it a hunch, but I bet their reaction to a clear majority of Americans being opposed to the wall will have a decidedly less “Trust the people” reaction in their ranks.

And while I’d agree with Allahpundit that anti-Trumpness is about 80% of the reason for this change, I would also suggest that, as Trump constantly reminds us, he has put The Wall at the center of the political debate this cycle. That means as an idea, it is getting both consideration and examination it might not otherwise have. Including the question of whether the effort and expense is any way an actual, worthwhile undertaking as a remedy for illegal immigration woes. Clearly people are concluding that, no, it isn’t. It is not some magic cure-all that will make America “great again.”

There is a lot more really interesting data in this Pew poll and we’ll unpack more of it at RedState today. But in the short term, know that Trump’s campaign has a negative effect on his core issues as well as any positive effect. The longer he continues to act like a jackass, the more lopsided the effects will be.