Barton Swaim is author of “The Speechwriter: A Brief Education in Politics.”

When I was young, my friends and I would support our more improbable factual claims by following them with the words “ask anyone.” One of us would make a preposterous statement, another would say it wasn’t true, and the response would be something like: “Sure it is. Ask anyone.” In time, we would learn that the rules for corroborating assertions were more stringent and that disputable claims required either reasoned argument or reference to a reputable source.

Lately, though, I’ve wondered whether some journalists are relying too much on the “ask anyone” method of citation. Its more sophisticated form appears in a passive-voice clause that includes the word “widely”: “widely believed,” “widely suspected,” “widely thought,” “widely considered,” and so on.

Clearly, there are some beliefs or suspicions that really are shared “widely,” and there is nothing wrong with saying so. When a Telegraph reporter writes that Malaysia Airlines Flight 17 is “widely believed to have been shot down by a surface-to-air missile fired by Russian-backed separatists,” that’s reasonable. The connection can’t be documented with finality, not yet anyhow, but almost everybody believes it.

Just as often, though, that little word “widely” seems designed to appear to do the work of citation or argument without actually doing it. You can sense the author’s thought process: If he writes “U.S.-British relations are thought to be at their most strained in decades,” the obvious question is, “Thought by whom?” But if he inserts a “widely,” the problem somehow goes away. “U.S.-British relations are widely thought to be at their most strained in decades.” Ah, well, if it’s “widely” thought, it’s probably close to the truth.

Consider this passage, from a recent article in the Economist on the trend toward greater college enrollment by women: “Numbers in many of America’s elite private colleges are more evenly balanced. It is widely believed that their opaque admissions criteria are relaxed for men.” Maybe it’s “widely believed” and maybe it isn’t — it depends on what “widely” means — but that allegation is a serious one, and it deserves more support than a casual allusion to what’s “widely believed.”

Similarly, an article published on the website of San Francisco’s public media outlet KQED explained some Democratic congressional leaders’ reluctance to support the Iran deal. “It’s widely suspected,” we learn, “that many of these elected leaders have been influenced in part by powerful conservative pro-Israeli lobbying groups like the American Israel Public Affairs Committee, which strongly opposes the agreement.” The passive voice, together with the vague qualifiers “many” and “in part” — “it’s widely suspected” (who suspects it?) that “many” lawmakers were influenced “in part” by lobbyists — allows the writer to make an unsubstantiated opinion sound like unassailable fact.

Sometimes writers attempt to use a “widely” clause to validate an observation but make nonsense of it in the process. From a recent article in the New York Times: “In the early years of the AIDS crisis, it was widely believed that the threat to women via sexual transmission was overblown.” But that belief couldn’t have been very “widely” held if the threat was over-hyped — right? And again, in an otherwise fine piece on British novelist John Cowper Powys in the Telegraph, we read that “his name remains little known, even though he wrote what are widely thought to be at least three other great novels.” If the greatness of those novels is so “widely” appreciated, how can Powys’s name remain little known?

By far the most insidious use of “widely,” however, occurs when the word refers to a manifestly small number of people who nonetheless share the writer’s view. Earlier this year, for instance, a writer for the Los Angeles Times began his column by noting that “it is widely held that the dopiest anti-Obamacare lawsuit is King vs. Burwell.” And an editor at the New Republic observed that Sen. Ted Cruz (R-Tex.) is “widely considered one of the most socially inept candidates.” Maybe both these statements are true and I am irritated by them only because, not sharing the writers’ political views, I am not included in their uses of “widely.” But when the New Yorker, in a highly flattering profile of Secretary of State John Kerry, refers offhandedly to “George W. Bush, who is widely considered the worst President of the modern era,” I am pretty sure that that “widely” does not mean what most of us mean when we use it.

Surely a “widely considered” opinion must be shared by almost everyone who has an opinion on the subject. In any case, most people do not actually believe George W. Bush to have been the worst president of the modern era. Ask anyone.