Brad DeLong is mad at Tyler Cowen, with reason — for Cowen writes about US fiscal irresponsibility, fairly sensibly, without mentioning the elephant, and I do mean elephant, in the room: the role of the post-Reagan GOP.

Look: until 1980 or so the United States generally paid its way; the ratio of debt to GDP generally fell over time. Then starve-the-beast came to power, and fiscal realism went away. That’s the story; anyone who glosses over that, who makes it a plague-on-both-houses issue or, worse, makes it seem as if Obama is the villain, is in an essential way misleading his readers.

Bear in mind, too, that the signature initiatives of Republican presidents — the Reagan tax cut, the Bush tax cut, the Medicare drug benefit — have all been unfunded deficit-raisers; the signature initiatives of Democratic presidents — the Clinton tax hike, Obamacare — have all been deficit-reducing. (Yes, the stimulus — but that was intended to be temporary, and has in fact proved too temporary; and Bush I’s tax increase was an exception, but the GOP has made it clear that nothing like that will ever happen again.)

Democrats aren’t fiscal saints. But we have one party that has been generally responsible, and tries to pay for what it wants, and another party that consistently, deliberately, takes actions to increase deficits in the long term. Saying this may be shrill; but not saying it is being deceptive.