Earlier this week, President-elect Donald Trump’s former campaign manager declared that it was once again safe to say “Merry Christmas,” reflecting Trump’s campaign promise that, if he won, every store would say “Merry Christmas,” and “Happy Holidays” would be out. Trump had previously called out Starbucks holiday cups for being insufficiently Christmas-oriented, a criticism shared by many people on social media for the second year in a row. Gap, Target, The Home Depot, and many other retailers have been criticized in the past. The now-annual controversy over the “war on Christmas” highlights the difficulties now faced by any company that wants to avoid offense in the run-up to the winter holidays.

In a December 2005 Gallup poll, 41% of respondents said they preferred to be greeted with “Happy Holidays” during the holiday season, and 56% said they’d rather hear “Merry Christmas.” Ten years later, a survey we conducted at Fairleigh Dickinson University’s PublicMind research center found that only 25% wanted to hear “Happy Holidays,” while 65% of Americans said they preferred “Merry Christmas.” Despite variance between pollsters and different ways of wording the question, the trend is clear: Over the last decade, many Americans changed their minds about the greeting they want to hear, and the question of what to say to customers and neighbors became fraught with social meaning. This change — and the very idea of a war on Christmas — seems to be the result of coverage on one channel: Fox News.

This isn’t to say that Fox hosts originated the idea of a war on Christmas. The term arose in the writings of anti-immigration activist Peter Brimelow in 1999 but languished until October 2005, when John Gibson appeared on The O’Reilly Factor to discuss his new book, The War on Christmas: How the Liberal Plot to Ban the Sacred Christian Holiday Is Worse Than You Thought.

The thrust of the argument made by Brimelow and Gibson is that governments and large corporations are actively pushing an anti-Christian agenda. For instance, Gibson points out that in 2004 Amazon wished its customers “Happy Holidays” rather than “Merry Christmas,” some schools listed a “Winter Break” on their calendars rather than a “Christmas Break,” and the holiday stamps put out by the U.S. Postal Service featured a snowman (a point perhaps undercut by the fact that religious-themed stamps were also available). In Gibson’s argument, it all was part of a secularist plot that aimed to, as O’Reilly put it on November 18, 2005, “get religion out, [so] then you can pass secular progressive programs like legalization of narcotics, euthanasia, abortion at will, and gay marriage.” But it is not just the government that is threatening Christianity, Gibson claimed: “Every time a supermarket checker or store clerk greets you with [‘Happy Holidays’] instead of ‘Merry Christmas,’ you have met another soldier in the War against Christmas.” In this view, saying “Merry Christmas” is a political act, announcing one’s opposition to secular liberals, in what Michael Norton from Harvard Business School and Samuel Sommers from Tufts University describe as a symbolic protest against a perceived loss of privilege.

From 2005 on, Fox News has returned to the topic every year, while noncable television networks and major newspapers have given it little to no coverage, mentioning it only a handful of times, and never seriously. Most of the discussion about it outside of Fox has been on MSNBC and The Daily Show, both of which have used it to mock Fox’s coverage.

The argument that saying “Happy Holidays” is the spear tip of a concerted secularization plot may seem like a stretch, but it seems to have been accepted by many Americans. In a December 2013 national PublicMind poll, 28% of Americans agreed or strongly agreed with the statement, “There has been a concerted effort by politicians to take ‘Christ’ out of Christmas.” Forty percent of Republicans agreed (33% strongly), compared to only 16% of Democrats. As might be expected, frequent churchgoers (those who attend once a week or more) are more likely to think there’s a war on Christmas (in the survey, we avoided using that exact term so that respondents wouldn’t be tipped off to the research question we were exploring), with 35% agreeing.

Watching Fox News doesn’t make someone more likely to be concerned about secularization, but it does have a significant effect on people who don’t go to church much in the first place. Among individuals who say they seldom go to church, watching Fox News increases the likelihood of agreeing that there’s a war on Christmas by five points; among those who say they never go to church, the difference is 10 points. In effect, watching Fox News makes less religious people as concerned about secularization as those who go to church frequently. It seems that the rhetorical strategy employed by Fox News commentators has worked. By making the “war on Christmas” just one front in a general political conflict, Fox News has made its viewers, even those who normally wouldn’t be worried about religious issues, more likely to accept the war’s existence. That effect, which links concerns about secularization and “Happy Holidays” to a political identity, seems to be the driving force behind the increase in preferences for “Merry Christmas” and in disdain for alternatives.

What’s amazing about this is that coverage on one cable channel has led to a large section of the American public changing their everyday behavior and the way they view the behavior of others. It means that business owners’ decisions about something as innocuous as a holiday greeting have become viewed through a political lens that owners and managers wouldn’t have considered before. It’s easy to imagine that we live in a post–mass media world, one in which no single news source can have a real impact on our society. In this case, one news outlet still retains the ability to move the opinions and behaviors of the American public.