In the home stretch of the presidential campaign trail, John McCain has been saying that his opponent Barack Obama is so sure that he's bound for the White House that he's already "measuring the drapes." It's a durable political expression, though very often it's said as "measuring for drapes" (which makes a bit more sense), and sometimes it's curtains that get presumptuously measured (for), rather than drapes. What's the difference, anyway?

I looked into the history of drape- and curtain-measuring after reading Richard Leiby's dissection of the expression in the Washington Post. The earliest appearance that Leiby uncovered was from 1980, in a New York Times reference to independent presidential candidate John Anderson: "Obviously, it's much too soon for Mr. Anderson to start measuring for drapes at 1600 Pennsylvania Avenue."

By searching on both drapes and curtains I was able to push the date back a few decades earlier. Martha Taft, wife of Senator Robert Taft, was suspected in 1940 of wanting to "change the drawing-room drapes in the White House." Then in the spring of 1968, the columnist Jack Wilson joked that after Bobby Kennedy jumped into the Democratic primary, he wanted to talk to President Johnson so that his wife Ethel could "get in to measure for curtains." And in October '68, Hubert Humphrey said of Richard Nixon, "Why, he's even been to Washington to look at the White House and measure for drapes." (You can read more about the history of the expression in my recent Language Log post, which got picked up by the New York Times political blog, The Caucus.)

Users of the political cliché have freely alternated between drapes and curtains. The Visual Thesaurus treats them as synonyms, sharing the sense "hanging cloth used as a blind (especially for a window)," but some make a more fine-grained distinction. The website Well Dressed Windows, for instance, says "Drapes are pleated and are more formal, whereas curtains are informal and generally gathered." Curtains are historically older, referring to window coverings since the early eighteenth century, while drapes emerged in North American usage in the late nineteenth century. In a comment on my Language Log post, Boston Globe language columnist Jan Freeman provides some more background:

Drapes vs. curtains nowadays designates more formal vs. less formal, but drapes was socially taboo for some decades. In the 1950 edition of Etiquette, Emily Post says:

Drapes — this word is an inexcusable vulgarism.
Curtains are hung at a window; hangings as decoration of walls. It is true draperies would be correct for many loopings or shirrings or pleatings, especially on a woman's dress.

(There's no mention of drapes in the 1922 edition of Post, so presumably the usage problem had not yet arisen.)

Miss Manners, at least as late as 1983, concurs, calling drapes and drapery faux-elegant commercial words.

Miss Manners might think it's faux-elegant, but drapes are pretty well established in American usage for formal window treatments, the kind you'd find in the Oval Office. As drapes have developed fancier connotations, curtains (once a catch-all term) have been pushed into less formal territory — gathered rather than pleated, according to Well Dressed Windows. This kind of semantic shift reminds me of how in the U.S., home has largely displaced house in the language of realtors, to the point that townhouses are now routinely called townhomes. Sometimes a previously serviceable word can be shunted aside in favor of something a bit more genteel.