The Democratic Strategist provides an enlightening examination of political polarization, elections, and the popular vote, taking a close look at both recent elections and historical polling data in order to give us an idea of where we are headed. It seems we've been "self-sorting."
While there is no evidence that the electorate's overall ideological balance has changed much over the past three decades, voters are being sorted: fewer self-identified Democrats or liberals vote for Republican candidates than they did in the 1970s, fewer Republicans or conservatives vote for Democratic candidates, and rank-and-file partisans are more divided in their political attitudes and policy preferences. Also, religiosity (not to be confused with the denominational hostilities of the past) has become a telling determinant of political orientations and voting behavior. All else equal, individuals who attend church frequently are more likely to regard themselves as conservatives and vote Republican.Increasingly, the electorate has adopted the "I think X, X and X, so I am obviously (Insert Political Party of Choice)" way of thinking and voting (or worse yet, and more common, "I am (Insert Political Party of Choice) therefore I think X, X, and X).
Politics has become, for both voters and candidates, less about voting for the right person for the issues that matter to us, but more about the "Hard Sell." We willingly place ourselves into the group that better convinces us they represent us during an election, rather than finding substansive information about the candidates and issues.
...people as a whole are not shifting their ideological or policy preferences much. Rather, they are being presented with increasingly polarized choices, which force voters to change their political behavior in ways that analysts mistake for shifts in underlying preferences. A plausible inference is that if both parties nominated relatively moderate, nonpolarizing candidates, as they did in 1960 and again in 1976, voters' behavior might revert significantly toward previous patterns. Another possibility is that changes at the elite level have communicated new information about parties, ideology, and policies to many voters, leading to changes of attitudes and preferences that will be hard to reverse, even in less polarized circumstances.