One of the issues baffling non-conservatives in assessing the latest stage of the fiscal conflict in Washington is that Republicans are treating Democratic demands for loophole-closing on the wealthy exactly like it’s a tax rate increase. That’s odd, since it’s Republicans who have continuously injected loophole-closing–or as they usually call it, “tax reform”–into the debate. For years they’ve discussed it as a possible way to finance a revenue-neutral tax rate cut. Paul Ryan made it (or at least a very vague version of it) central to the math and marketing of his various budget proposals. During most of the 2012 campaign, Mitt Romney touted “tax reform” in the more traditional way, as a magic asterisk that would both limit revenue losses from the tax rate cuts he was proposing, and would also (even less plausibly) prevent his overall plan from changing the distribution of the tax burden. After the election, “tax reform” became part of the package Republicans supported as a “fiscal cliff” measure to maintain all the Bush tax rate cuts.

But Republicans have always been reluctant to talk about tax reform if it’s used for any purpose other than reducing tax rates or avoiding higher tax rates, even though conservative economists tend to support loophole-closing as an efficiency measure worth taking in isolation from rate changes.

So once the battle over tax rates ended (temporarily) with the so-called “fiscal cliff” agreement, Republicans quickly declared not just tax rates but any additional revenues as off-limits in future agreements. So even though you’d think they’d be at least as open to a tax-reform-for-entitlement-reform deal as they were for a tax-rates-for-entitlement-reform deal last year, that has not been the case. It’s tax rates that continue to drive GOP tax policies, even in the absence of any real chance that they will soon be raised or lowered.

Here’s how Jonathan Chait explains what he calls this “reversion to form:”

The answer to this piece of the mystery is clear enough: Republicans in Congress never actually wanted to raise revenue by tax reform. The temporary support for tax reform was just a hand-wavy way of deflecting Obama’s popular campaign plan to expire the Bush tax cuts for the rich. Conservative economists in academia may care about the distinction between marginal tax rates and effective tax rates. But Republicans in Congress just want rich people to pay less, period. I can state this rule confidently because there is literally not a single example since 1990 of any meaningful bloc of Republicans defying it.

What has aided the easy reversion to form, with low taxes for the rich dominating all other considerations, is the pent-up rage and betrayal John Boehner has engendered among his most conservative members. Almost nothing Boehner has done since taking over as speaker has endeared him to his ultras. Every subsequent compromise creates more embitterment, and the last few moves have provoked simmering rage.

Conservatives had to swallow a tax hike, and then swallow an increase in the debt ceiling. Boehner has, incredibly, had to promise his members that he will not enter private negotiations with Obama.

The pressure for confrontation as a method has built up to the point where seemingly no deal Boehner could reach would leave him safe.

So Republicans aren’t open to the tax reforms they’ve supported in the past, or to entitlement reforms they’ve been demanding for years (though this particular issue is complicated by the fact that they only want “entitlement reforms” if they significantly reduce actual benefits; anything else can’t possibly be a “reform”). They have truly painted themselves into a corner this time, and that’s why we are going to have a sequester followed quite possibly by a government shutdown if Democrats resist making the domestic spending part of the sequester permanent.

Our ideas can save democracy... But we need your help! Donate Now!

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.