Gallup’s analysis reveals that the changes in seniors’ party preferences are attributable in part to attitudinal change among today’s seniors as they have aged. This is evident in survey results from 1993 and 2003 that show the party preferences of today’s seniors when they were 10 or 20 years younger.

In 1993, Americans then aged 45 to 79 represented the age group that today is 65 to 99. At that time, 20 years ago, those 45 to 79 were highly Democratic, with a 12-point advantage in favor of the Democrats. That gap was larger than the average seven-point Democratic advantage among younger age groups that year.

Ten years later, all age cohorts had become more Republican and were fairly balanced politically. Today’s seniors, who were aged 55 to 89 in 2003, were the only age cohort to tilt Democratic at that time. The 2013 results show that today’s seniors have continued to move in a Republican direction, while the younger age cohorts have gone back in a Democratic direction.