The Republicans’ cut-cap-and-balance plan — perhaps better know to readers of this blog as The Worst Idea in Washington — will get a vote this week. The proposal would, among other things, cap federal spending at 18 percent of the previous year’s gross domestic product. The last time we were anywhere near there wasn’t during George W. Bush or Ronald Reagan. It was in 1966. The Center for American Progress has an informative graphic tallying up some of the changes between now and then: