Drew DeSilver of the Pew Research Center –
Ken Feltman: This information may be five years old but it continues to be among the best available.
American political parties have long been vehicles to represent ever-shifting coalitions of particular interests — economic, regional, social and ideological. For example, Great Plains farmers who often voted Democratic a century ago now solidly favor Republicans; African Americans who were loyal GOP voters for decades after the Civil War began shifting during the New Deal and now are overwhelmingly Democratic. Political observers can still spend hours of pre-election time ruminating over whether the “big-city ethnic vote” or the “farm vote” will prevail.
But the parties also are coalitions of distinct groups of voters, whose shared attitudes and values unite them — and shape the parties they incline toward — at least as much as more impersonal economic and societal forces.