Polls, Party Preferences, and Polarization

The Pew Research Center's web site includes a page entitled The 2004 Political Landscape: Evenly Divided and Increasingly Polarized. The first graph on that page shows party identification in the U.S. between 1937 and 2003. The graph also (unintentionally) shows why polls are so unreliable:

1. The incumbent president's popularity strongly affects what people tell pollsters about party affiliation. There has been a consistent swing toward the opposite party as the popularity of incumbent presidents has waned or plummeted. This phenomenon can be seen toward the end of every presidency from Truman's through Clinton's, and most notably toward the end of Nixon's disgraced presidency.

2. The core of each party's constituency has changed drastically during the past seven decades. Remember when New England was reliably Republican and the "Solid South" was a bastion of the Democrat Party? Remember when there was more than a handful of liberal Republicans and conservative Democrats in Congress? The realignment of party affiliations wasn't sudden. It began in 1948, when many Southerners found it possible not to vote for a Democrat. It continued in 1952, when popular Ike ran as a Republican. It accelerated in 1960, when the Democrats nominated Catholic JFK, much to the consternation of many Southerners. It got another boost in 1968, when Democrats got on the wrong side of the culture war. And it continued well into the 1980s, thanks largely to Carter's ineptness and the left's continuing dominance within the Democrat Party. Polling results about party preferences were largely meaningless during the 40 years from 1948 to 1988 because personal as well as regional party alignments were in almost constant flux during that period.

Pollsters -- and pundits -- are nevertheless fond of drawing sweeping inferences from flawed statistics. An inference that has played prominently since the close presidential election of 2000 is that the nation has become "polarized." That is, many States have become reliably "Red" (Republican) and "Blue" (Democrat), instead of vacillating from one election to the next. In this case, the pollsters and pundits are right, but they would have been just as right in the 1940s and 1950s, when Republicans reliably held New England and Democrats solidly held the South. So why is "polarization" now such a big issue?

It's a big issue because the Democrat Party no longer enjoys the large (but illusory) plurality that it enjoyed from New Deal days until the 1980s. "Polarization" is bad only if it means that your favorite party is no longer the dominant party.

The underlying fear, of course, is that today's "polarization" may become tomorrow's Republican dominance. As another graph on the Pew page indicates, Democrats tend to be older than Republicans. That is, Democrats are dying at a faster rate than Republicans.