It's been three weeks since the moderate Sen. James Jeffords fled a Republican Party he felt he could no longer call his own. In the wake of his move, the media have panted after tidbits hinting who might jump next. Will it be war-hero maverick John McCain of Arizona? Or might it be Mr. Jeffords's fellow New Englander, Lincoln Chafee of Rhode Island?
In some ways, the focus on personalities misses the larger point. The Jeffords defection is only the most recent example of an extensive sorting process that is making the two parties ideologically tidier - and reducing the areas of overlap between them.
This shrinking of the political center in Congress is in large part the result of a realignment that began during the civil rights era, in which Southern Democrats started switching to the Republican Party and Northeastern Republicans turned to Democrats.
Its implication: Consensus in Congress is likely to become more difficult, as the starting point for most legislation moves further from the center and more contentious issues (such as prescription-drug benefits or judicial nominees) start to come up.
"Each party has become more internally homogenous, and the centers of gravity have become further apart," says David Rohde, a political scientist at Michigan State University in East Lansing. "The downside, from the voter's point of view, is that ... it makes it more difficult for the parties to work together. This is particularly true in circumstances like we have now in Congress, in which the center is mostly unoccupied."
Perhaps the clearest proof of this distillation of party identity is voting records. Thirty years ago, lawmakers voted along party lines only about 60 percent of the time, according to Congressional Quarterly statistics. But in recent years that number has topped 80 percent.
Likewise, in 2000, every GOP senator except two had a more conservative voting record than even the most conservative Democrats, according to National Journal. (The two exceptions: Senator Jeffords of Vermont and Senator Chafee of Rhode Island.)
One reason for this greater party discipline is political realignment. Democrats used to dominate the South in part because Republicans were the party of Lincoln and the Union in the Civil War. Since the 1960s, that legacy has faded as Southerners switch to a GOP they feel better reflects their conservative values. Northeastern Republicans, in turn, have become an uneasy fit in a party defined less and less by its heritage of emancipation and a sense of noblesse oblige.
The political process is also sharpening party definitions. Mr. Rohde says moderates on both sides have been driven out in part because it's hard for them to get nominated anymore. "Activists in the Democratic Party are so left wing, and those in the Republican Party are so right wing - and they tend to dominate the process."
The electorate, on the other hand, is increasingly becoming centrist and independent - which means they often don't participate in the process of selecting candidates, since many states don't let independents vote in primaries. As a result, "the public are increasingly disaffected from the parties," says David King, a Harvard University political scientist.
Although party polarization has been occurring gradually, it became particularly acute during the Clinton years. Indeed, the year with the highest percentage of party-line voting was 1995, directly following the Republican takeover of Congress. Of that new class of GOP senators, six were ranked by National Journal as among the 10 most conservative senators for the year 2000.
Yet given the current slim margins of control, neither party can afford to alienate the remaining moderates on their side.
In the wake of the Jeffords shift, Mr. Bush has made a point of reaching out to Senator Chafee and Senator McCain.
Despite these efforts, the Republican Party has had a difficult time lately convincing the public that it still possesses a big tent.
When asked in a recent ABC News/Washington Post poll which party was more open to the ideas of moderates, 57 percent of Americans said Democrats; 32 percent chose Republicans.
Trent Duffy, spokesman for the Republican National Committee, disagrees with the perception that the GOP has abandoned the center. He points out that Republicans once wanted to abolish the Department of Education, and are now prepared to pass a major education bill.
Moreover, he argues that the increased cohesion in voting patterns is more a function of numbers than ideology. "When you have such slim margins, party unity is a lot more important," he says.
Still, other analysts say the party as a whole has moved measurably to the right. "Those who we refer to as moderates are more conservative than those considered moderates 30 years ago," says Norman Ornstein, a congressional expert at the American Enterprise Institute here.
And while some party leaders have made a show of reaching out to those remaining moderates, many right-wing activists have indicated they'd prefer to get rid of the centrist element altogether.
But purists on either side who see total ideological consistency as the goal aren't doing their party any favors, say analysts. "That's just stupid, because in the end it comes down to math," says Mr. King.
Mr. Ornstein agrees: "For those who want pure parties, we can give them a one-word definition: minority."
(c) Copyright 2001. The Christian Science Monitor