Yglesias writes:
John McCain would like us to believe that he was some kind of uber-prescient early critic of the Bush administration's tactics in Iraq but it's just not so. Barack Obama warned before the war that disaster was likely, McCain cheerleaded for war.
leading a commenter to write:
"Cheerleaded"? My respect for a Harvard education drops another notch...
Now, Yglesias just plain can't spell, but this raises the question: What is the past tense of the verb "cheerlead"? I'm pretty sure that "cheerlead" is backformed from the noun "cheerleader" (apparently first recorded in 1903). According to Steven Pinker, whenever an irregular verb is turned into a noun and then back into a verb, it becomes regular: "flied out" in baseball, "grandstanded." (I call fouls on "high-sticked" and "ringed" [UPDATE: That is, I don't think they're examples of the phenomenon he's discussing], given that the nouns those verbs are derived from aren't etymologically related to the irregular verbs -- note in fact that "ring" meaning "make a ring around" goes back to Old English.)
Blargh earlier mentioned "mini-break"/"mini-broke" in tennis as exception to Pinker's rule. What about the past tense of "cheerlead"? Googlefight tells all: "Cheerleaded" beats "cheerled" 6240 to 3580. So there's more support for "cheerleaded," but "cheerled" is out there; which I think contradicts Pinker's hypothesis. (Admittedly the first few screens for "cheerled" contain very few examples of actual use in sentences, but if you go deeper in people are using it.)
American Heritage recommends "cheerled," on what authority I don't know. Note that the past tenses of "cheerlead," and "cheerleads" are much less common than "cheerleader" -- not surprising, given the origin as a noun -- but also than "cheerleading" and "cheerlead," which I find slightly odd, given that both of those are verbal forms. (There are a lot of false positives in "cheerlead"; "to cheerlead" is about three times more common than "cheerleads," which makes it much less common than "cheerleading.")
Previous discussion of irregular verbs here.