Political polarization intensified during the 2004 elections, continuing a trend that has defined voting behavior for most of the past decade and that has left the two major parties increasingly homogenized and partisan.
Only 59 of the 435 congressional districts went in different directions in presidential and House elections last year, according to newly released data from the political analysis firm Polidata. In the remaining districts, voters either backed both President Bush and the Republican House candidate or John F. Kerry and the Democratic House candidate.
The findings came as no surprise to election experts but as confirmation of patterns that now appear ingrained in American politics. In 2000, there were 86 such "split-ticket" districts, and in 1992 and 1996, there were more than 100 such districts.
The steady decline in districts where voters pick different parties to represent them in the White House and Congress reflects in part the effects of the redistricting process, which has created more and more strongly Republican or strongly Democratic districts. But the trend also underscores what political scientists and party strategists have known for several years, which is that party identification is now a powerful indicator of how someone votes in national elections.
"You have parties that are ideologically more homogenous than they used to be and you have congressional parties that are more active in partisan activities all the time, rather than just closer to the election," said Mark Gersh of the National Committee for an Effective Congress, an organization that provides Democrats with analysis and advice about congressional and presidential voting patterns.
Polidata's Clark Bensen said that Bush carried 255 congressional districts on his way to winning reelection last November, while Kerry won 180. The president captured 214 districts held by congressional Republicans and 41 districts that were won by Democratic House candidates. Just 18 of the districts that Kerry won are in GOP hands.
"People are getting much more into two camps," Bensen said.
That has increasingly been the case since the mid-1990s, and the 2004 presidential exit polls underscored that. In the presidential race, 93 percent of self-identified Republicans backed Bush and 89 percent of Democrats supported Kerry. Independents went 49 percent for Kerry and 48 percent for Bush.
In the more distant past, voters were far more likely to split their tickets when voting for Congress, particularly in the era when the South was heavily Democratic, albeit conservative. But the GOP takeover of the South, and to a lesser extent the decline of Republican moderates and liberals in the Northeast, has produced the new patterns.
Bensen's figures show again the depth of the Democrats' problems in the South. Not only did Bush carry every southern state, he carried the overwhelming percentage of congressional districts, except those where minorities are in the majority. Bush carried 116 southern congressional districts, Kerry just 38. According to Bensen, just three House Republicans from the South occupy districts won by Kerry, while almost two dozen southern Democrats are in districts carried by Bush.
Redistricting has produced far fewer competitive congressional districts, a fact that has lead to greater polarization in the conduct of the House. Those heavily partisan districts often produced landslide victories for either Bush or Kerry. At a time when the national vote was 51 percent for Bush to 48 percent for Kerry, 215 of the 435 House districts were decided by 20 points or more. Bush won 116 districts with more than 60 percent of the vote, while Kerry won 88 districts by similarly large margins.
Bush captured more congressional districts last November than he did in the disputed election of 2000, although one reason is that the post-2000 census shifted more congressional districts to states he won that year.
How would Bush and Kerry have fared if the electoral college determined its allocation of electoral votes on the basis of who won each congressional district, as some advocate, rather than on who wins the popular vote in each state? Bensen crunched those numbers and concluded that Bush would have won by an even larger margin, with 317 electoral votes rather than the 286 he actually captured.