It is indeed a grand old flag for the Grand Old Party.

Donald Trump gives a speech as he announces his candidacy for the United States presidency at Trump Tower in New York City. (Photo: Christopher Gregory/Getty Images)

The 2016 Democratic presidential candidate will probably get some bad advice as the general election campaign begins. Some adviser will insist her advertisements should prominently feature the American flag, to neutralize any impression she is less than patriotic.

Don't do it, Hillary. It'll just win votes for your Republican opponent.

So suggests some newly published research, which confirms and refines a 2011 study that found simply seeing the stars and stripes nudges voters toward the GOP. This new paper reports that dynamic is restricted to a subset of Americans—but for them, it occurs even when the flag is used to promote a Democratic candidate.

"We find that flag imagery has subtle pro-Republican effects on vote choice, regardless of (its) source," write political scientists Nathan Kalmoe of Monmouth College and Kimberly Gross of George Washington University. In contrast, they add, "Democrats find no advantage from using the flag."

The Donald Trump campaign could solidify its support among key constituencies through the use of the flag.

In the journal Political Psychology, Kalmoe and Gross describe three experiments that lead to this conclusion. All were conducted online, and had similar structures.

After giving information about themselves, including their level of patriotism, political knowledge, and "attitudes towards racial, ethnic, and religious groups," participants in the first two experiments (conducted in the fall of 2012) read information about the two major-party presidential candidates, Democrat Barack Obama (who was running for re-election) and Republican Mitt Romney. They then indicated who they planned to support.

For the third experiment, conducted the following year, participants similarly evaluated possible 2016 candidates Joe Biden and Paul Ryan, afterwards noting which of the men they preferred.

"Each candidate's photo was embedded at the top of the survey page individually evaluating them," the researchers write. For some participants, an American flag was placed in the background of the photo; for others, it was absent.

Combining the results of all three experiments, "we find flag exposure weakly but consistently benefits Republican candidates," the researchers write. "Not only do flags tend to benefit Republican candidates—this is so even when flags appear with Democrats."

Further analysis of the data revealed this "flag effect" is largely confined to "voters who are more patriotic, who see whites more favorably than blacks, and who identify more strongly as Republicans."

"Rather than diminishing the role of race by signaling shared values," they add, "the American flag amplifies the impact of racial attitudes in vote choice."

It isn't clear whether these findings apply only to the current political environment (dominated by a Democratic president who is both black and seen by many as an "outsider"), or to American campaigns in general. If the latter is true, "it poses a no-win situation for (Democratic) candidates," the researchers write. "Appear with the flag and encourage votes for your opponent, or avoid the flag and give your opponent a patriotism cudgel to wield as a campaign issue. While penalties for either choice won't routinely decide elections, they could be pivotal in close contests."

The findings suggest the Donald Trump campaign could solidify its support among key constituencies through the use of the flag, while candidates attempting to appeal to a more diverse demographic would be better off avoiding such imagery.

Old Glory is supposed to be a symbol of national unity, but this research finds it symbolically resonates most strongly with a specific subset of Americans, reinforcing their values and reminding them which political party shares those beliefs. Which, if you're a Democrat, isn't all that glorious.

Findings is a daily column by Pacific Standard staff writer Tom Jacobs, who scours the psychological-research journals to discover new insights into human behavior, ranging from the origins of our political beliefs to the cultivation of creativity.