Many, many who vote conservative, used to be liberal. Haven't you learned that most people turn conservatives as they get older? After growth, and learning more about life and politics, people tend to turn conservative...
The writing on the wall is plain and simple.
Through experience, people can perceive what politics actually effect their life/family/bottom dollar. The 40yo dumbass has seen president's come and go. The 20yo dumbass might not even have voted for a president yet. But which dumbass probably has a better formed opinion?