What we might have done instead
A revisiting of history on the presidential campaign trail provides an occasion for reviewing may and might.
Historical revisionism may have gotten a boost last month on the presidential campaign trail. A candidate made what were interpreted as approving noises in reference to the internment of Japanese-Americans during World War II.
This internment is widely seen as one of the great American public policy blunders of the 20th century, and a blot on the record of President Franklin Roosevelt, who ordered it. But one of the leading presidential contenders is not so sure. In an interview touted as “exclusive,” he said he didn’t know whether he would have supported or opposed the internment of Japanese-Americans during World War II.
And so “the news” out of the interview was that the man did not say unequivocally that the internment was a bad thing. This led to an article whose headline – as it appeared in some contexts, at least – was “[Candidate] May Have Backed Japanese Internment During WWII.”
The copy-editing world was briefly abuzz over this – not on the politics of the issue, at least not overtly, but on the grammar of it. The candidate wasn’t born until after the end of World War II and thus couldn’t have “backed” anything during it. The situation was a “counterfactual” or hypothetical rather than an open possibility. And so the headline should have read, according to the traditional view, “[Candidate] Might Have Backed Japanese Internment During WWII.”
Headline writers everywhere, though, are squeezed for space and time, and so they have an incentive to regard may and might as synonymous. The may/might distinction is under pressure.
These two words are examples of “modals,” or modal verbs. That’s the term for must, should, and similar words used to “express ideas such as obligation, permission, possibility, and intention,” as the Macmillan dictionary puts it. You may have learned these as “auxiliary” or “helping” verbs. They cover situations that are not in the straight “indicative” mood – e.g., “Jack is walking the dog.”
In the present tense, may and might serve to express possibility, with, to my mind, may suggesting greater probability. Grammar Girl Mignon Fogarty seems to agree with me; she offers a helpful mnemonic: “I remember the difference by thinking that I should use might when something is a mighty stretch”; that is, less likely.
The American Heritage Dictionary has a long “Usage Note” on may and might in which it disagrees with Grammar Girl and me on the probability issue: “In practice ... few people make this distinction.”
The dictionary is in favor, though, of “might” rather than “may” in situations like the presidential candidate’s utterances on the Japanese-Americans’ internment.
To quote further from the Usage Note: “Keeping the two forms distinct reduces ambiguity. ‘He may have drowned,’ for example, is best used to mean that it is unknown whether the man drowned, not that the man narrowly escaped drowning.”