If you need a better reason to fly the U.S. flag, I can't think of one. You can access the study itself here, and an article about the study on the Fox News website. The researchers are faculty at the University of Chicago, Cornell University, and Hebrew University; their article has been accepted for publication in Psychological Science.
Fascinating, that the Republican Party is associated in voters' minds with patriotism. You couldn't buy that kind of good public relations. It's almost enough to make you feel sorry for Democrats.