I found the word, “at turns” in the beginning sentence of the article of Time magazine (September 18) titled, “How Mitt Romney’s Luck Ran Out” that reads:
“For a good long while, Mitt Romney was the luckiest man in politics. He joined the 2012 race as the default Republican front runner after more-formidable challengers chose not to run. His declared rivals were at turns ineffectual, ridiculous, or self-destructive — granting Romney a fairly easy, if occasionally fraught, path to the nomination.
I was almost overlooking the phrase, “at turns” as a commonplace idiom, but curiously enough I couldn’t find this phrase in any of Cambridge, Oxford, OALED, and Merriam-Webster Dictionary though they register “by turns,” “in turn,” “at every turn” “on the turn,” and you can name it.
On the other hand, GoogleNgram indicates track of pretty high usage of “at turns” dating back to 1840.
Because no dictionary I consulted does offer me the definition, I cannot get exact idea of ‘at turns.’ Is it the same as ‘at every turn,” “by turn(s),” "one after another,"or “respectively?” Is “at turns” a familiar idiom as these idioms?
Of course it’s freedom of the editors of dictionaries what words and idioms they pick up in their dictionaries. But I wonder why none of wellknown English dictionaries accommodates the idiom of which high incidence of use being evidenced in NGram.
Best Answer
As others have said, it's a general term conveying the idea of one by one.
I'd like to add, though, that at turns may have been used because there are two things that could be said to have come one after another: the candidates, and their gaffes. So, in no particular order: Bachman was perceived as ridiculous, Cain was perceived as self-destructive, Huntsman was perceived as ineffectual, etc.
The author probably didn't want to be so specific, partly because the correlation between candidates and gaffes isn't as clear-cut as I've indicated here, and partly because a single candidate may have compounded the said gaffes atop each other in a series of political missteps. So, an efficient way to convey this sentiment is to state the generality:
leaving the reader to work out the details of who stumbled when, and how each one stumbled. Meanwhile, the author can move straightaway to the main point of the sentence, which is that Romney had "a fairly easy, if occasionally fraught, path to the nomination."
I'd conclude that at turns is not idiomatic, but instead an efficient way to describe a sequence of people independently making a series of mistakes.