As people age, they become more liberal :

According to a new US study people who are 60-years-old and over become more liberal at a faster rate. The study suggests that the long-held belief about older citizens being more set in their ways politically isn’t true. The research, published in the American Sociological Review, showed that although change occurred in both the 18-to-39 and 60-and-over age groups, the movement among the older group was greater and was most often toward "increased tolerance rather than increased conservatism".