Nearly four years after what many perceived to be the most divisive presidential election in U.S. history, the country remains closely split on ideological lines, though experts say the contours of the divide have changed somewhat.

"This country's still awfully, awfully evenly divided," said Charlie Cook (search), editor and publisher of The Cook Political Report. "I think the presidential election is going to be awfully competitive."

A Gallup poll based on more than 40,000 interviews conducted throughout 2003 shows that 45.5 percent of voters identify with or lean toward the Republican Party and 45.2 percent identify with or lean toward the Democratic Party. The remaining 9 percent identify themselves as independents and express no proclivity to either of the major parties.

The numbers have shifted only a little since 2000, but represent a continuing setback for Democrats, who once enjoyed an edge in partisan affiliation. A decade ago, 49 percent of Americans identified themselves as Democrats and 40 percent identified themselves as Republicans.

Among the 7,382 state legislators nationwide, 49.995 percent are Republicans while 49.13 percent are Democrats, Cook said.

"Nothing could be more closely divided" than the American public, Sen. John Breaux (search) told reporters and activists at an event held by the New America Foundation, a newly organized think tank that measures political and policy trends coming out of Washington, D.C.

The Democrat from Louisiana, who is retiring this year from the Senate after having built a reputation as a centrist compromiser, said polarization of the parties means "moderate Republicans and conservative Democrats tend to become independents, where they vote for the person and not the party."

Although nationally the numbers are quite close, the states tell a different story. In the last decade, 41 states have shown at least some movement toward the Republican Party. Significant regional shifts have also occurred over the last 10 years.

Democrats are still more popular in the Northeast and along the Pacific Coast, but Democratic advantages in many Midwestern states have evaporated, with only Illinois and Iowa remaining solidly Democratic over the last 10 years, the Gallup Poll shows. The remaining Midwestern states are competitive, the poll suggests. 

Most Southern states, which 10 years ago were largely Democratic or competitive, are now solidly Republican. Ten years ago, Oklahoma, Alabama, and Georgia were solidly Democratic. Now, they are solidly Republican.

In the five states with the closest margins in the 2000 presidential election — Minnesota, Iowa, New Mexico, Oregon, and Wisconsin — Republicans made gains in the 2002 mid-term elections, said Bush-Cheney Campaign Manager Ken Mehlman (search), quoting a Pew Research Center survey.

Mehlman said that although the nation remains very closely divided, the red states — which represent Republican majorities — are getting redder and the blue states — representing Democratic majorities — are turning purple.

The geographic divide also breaks down according to population density. Traditionally, Republicans do well in the suburbs while city dwellers favor Democrats.

However, a new trend favoring Democrats is developing in the suburbs, said Cook.

"Close-in suburbs are voting more Democratic. The further out, the whiter, the more conservative, the more Republican it gets. The country is divided on social and cultural lines as well as geographic lines, but where people choose to live says a lot about what your politics are," he said.

Since 2000, Republicans have made gains in several constituencies that are traditionally Democratic, including women, Hispanics and Jews. All still favor the Democratic Party, but polling from the 2002 election shows that the margins have narrowed.

Bush has actively courted these constituencies, most recently announcing a new immigration proposal he hopes will be embraced by the Hispanic community.

The Gallup poll showed a continuing gender gap with men leaning toward the GOP, and women favoring the Democratic Party. Republican strategists point to recent exit polls to show that the Democratic lead among women has likely dropped since 2000.

According to the 2004 Annual Survey of American Jewish Opinion (search) released Jan. 12, the Jewish vote is still overwhelmingly Democratic, though the Republican Party has managed to nearly double its share of the Jewish vote.

The percentage of Jews who considered themselves Republican leapt from 9 percent in 2000 to 16 percent in 2003. More than half of those surveyed identified themselves as Democrats, and about one-third said they were independent.

"As the latest poll makes clear, Jewish voters continue to support Democratic candidates because of shared values and a common approach on important issues. Republicans' boasts that they will attract a major share of the Jewish vote will not work because their strategy is not based on substance or real issues," Democratic National Committee Chairman Terry McAuliffe said in a statement following the survey's release.

Other constituencies traditionally favor the GOP, but nothing should be taken for granted.

"I just don't accept the notion that Democrats should write a portion of the voters off," such as churchgoers or Southerners, said Rep. Harold Ford Jr. (search), D-Tenn.

In a speech last fall, Mehlman said that the 2004 presidential election could be as close as the 2000 race.

"Today, this is a country where national elections are not decided by 20 point margins. They are decided by 4 or 5 points," he said.

Despite the narrow margins, Cook suggested that the splits are more harshly divided than in the past. He noted that in his first job on Capitol Hill — as an elevator operator in 1973 — he observed that "the other person might be wrong, but (his rival) didn't think he was evil."