The most striking and disconcerting thing about the latest round in the budget war is that the debate within the Republican Party is proceeding on the basis of completely false premises. I don’t mean false in the sense of wrongheaded policy beliefs. I mean Republicans are debating their strategy as if President Obama’s offer consists solely of making rich people pay more taxes. They won’t acknowledge his actual offer, which includes large cuts to retirement programs. I keep writing about this. It’s crazy.

Ezra Klein talks to some Republicans, and reports that they express no awareness of Obama’s offer, and greet news of it with disbelief:

Would it matter, one reporter asked the veteran legislator, if the president were to put chained-CPI — a policy that reconfigures the way the government measures inflation and thus slows the growth of Social Security benefits — on the table? “Absolutely,” the legislator said. “That’s serious.” Another reporter jumped in. “But it is on the table! They tell us three times a day that they want to do chained-CPI.” “Who wants to do it?” said the legislator. “The president,” replied the reporter. “I’d love to see it,” laughed the legislator.

Klein greeted this hopefully, as evidence that the parties were divided only by a “failure of communication.” I’m not so sure.

One of the most useful sentences of all time was uttered by Upton Sinclair, who said, “It is impossible to make a man understand something if his livelihood depends on not understanding it.” People’s understanding of reality is filtered through a prism reflecting all sorts of things other than reality, self-interest being among them.

I have spoken to many Republicans, and very few of them actually believe that opposition to marginal tax rates is vital, let alone that it ought to supersede all other priorities. Very often, I discover that their beliefs rest on an objective misunderstanding of the situation.

Yet the anti-tax wing has managed to maintain control of the party’s agenda for many years. The information floating in the heads of members of Congress isn’t just the collection of the best data available to them. They read news largely from conservative news sources dedicated to framing issues from the perspective of the party’s decisions. They rely on like-minded partisans to help them make sense of the issues – especially on fiscal policy, which is complex. The small handful of people in the party who actually care about this stuff tend to be militant supply-siders like Paul Ryan.

All this is to say that, if Obama could get hold of Klein’s mystery legislator and inform him of his budget offer, it almost certainly wouldn’t make a difference. He would come up with something – the cuts aren’t real, or the taxes are awful, or they can’t trust Obama to carry them out, or something.