Conventions always feature flags, but this year’s display seemed part of a broader Democratic effort to claim the mantle of patriotism from Republicans. The event featured the theme of American greatness, with speeches by military leaders, veterans, and their families, and frequent “USA!” chants from the audience….

For politicians, embracing the flag seems like a no-brainer. What better way to assure voters that you have the national interest in mind than vigorous displays of patriotism?

But our research suggests that flag-waving might not benefit Democratic nominee Hillary Clinton – and may even help Donald Trump and the Republican Party instead.

Republicans have frequently emphasized patriotism in contemporary presidential campaigns. For instance, George H.W. Bush in 1988 criticized Michael Dukakis for vetoing a law that would have required teachers to lead their classes in the pledge of allegiance. In 2008, Republicans questioned Barack Obama’s patriotism because he did not consistently wear a flag pin on his lapel. And in 2012, our analysis found that 43 percent of Mitt Romney’s campaign ads featured an image of the American flag, while 34 percent of Obama’s did.

This might explain why Republicans in recent decades have “owned” patriotism as a political concept, along with policy differences on military affairs and related topics. While there’s nothing inherently partisan about patriotism, voters consistently see Republican candidates as more patriotic than Democrats. And voters with traditionally patriotic attitudes tend to cast ballots for Republicans.

Indeed, a highly publicized 2011 psychology study by Travis J. Carter, Melissa J. Ferguson and Ran R. Hassin found that subjects exposed to images of the American flag were more likely to express support for the 2008 GOP presidential nominee, John McCain.

In 2012 and 2013, we designed follow-ups to that study to determine whether Democratic candidates could inoculate themselves from criticisms of their patriotism by appearing with the flag. We reasoned that pro-Republican effects might disappear if the flag provided visual evidence of a Democratic candidate’s patriotism.

But we were wrong.