From a reader:

Hi Jonah,
Full disclosure: I’m a Conservative, Republican, Catholic, Engineer. Many would find this evidence of fundamental internal contradictions. I pull it off seamlessly. This data point may be relevant: I’m over thirty-five (in fact I’m two days away from forty-one).
Not one of DeLong’s reasons pass the smell test for me. In fact if anybody told me any one of those was his reason for being a Democrat I’d look around for the hidden camera. I have to concur with your other correspondent’s anecdote about young engineers. I’ve been surprised how many bright young supposedly scientifically trained people are tree-spiking knuckleheads, immune to reason, theory, logic and evidence (or lack thereof) on more than a few issues of interest in contemporary political discourse (The look of wonder on their faces if one questions the fact of global warming is actually worth the price of admission.) I thought it was just because I was getting old and cantankerous.
Who knew?