The elephant in the room

Paul Krugman writes:

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.

Brad DeLong offers further comment.