What is a battleground state? Is it the same as a swing state? Veteran Poll Watcher Karlyn Bowman tells us how to understand what all those polls mean as we head into the election. This is the first installment of Poll-Pourri online.

One of the reasons it is so hard to predict this year’s presidential contest is that the country is at a very unusual moment of partisan parity. The major pollsters conducted 13 surveys in June. In nine of them, George Bush and John Kerry were separated by 2 percentage points or less. John Edwards’ addition to the ticket gave Kerry a nice bump in one quickie poll (NBC), but two other instant polls (Zogby and CBS) continued to show the race at 2 points.

Gallup data illustrate just how closely divided the country is. When the survey organization looked at its party identification question in more than 40,000 interviews the survey organization conducted in 2003, 45.5 percent of those surveyed called themselves Republicans and 45.2 percent called themselves Democrats.

Things don’t get much closer than that. These numbers represent an extraordinary change over the past three decades. Harris Interactive’s data shows that the Democrats had a 21-percentage point lead over the Republicans on party ID in the 1970s, an 11-point lead in the 1980s, a 9-point lead in the 1990s, and, in Harris’s data, a tiny lead for the Democrats thus far this decade. Interestingly, there’s been no movement at all on the ideological identification measure. In Harris’s data, 18 percent of Americans called themselves liberals in the 1970s, 1980s, 1990s, and thus far this decade. About a third consistently identified themselves as conservatives, although that number ticked up briefly during the Reagan years. Most Americans feel comfortable in the middle.

So, where does that leave us 107 days before the election? Nearly all analysts agree that the race will be decided in 16-18 states that were decided by 6 points or less in 2000.

The 16 states the major pollsters agree will be battlegrounds are: Arkansas, Florida, Iowa, Maine, Michigan, Missouri, Minnesota, Nevada, New Mexico, New Hampshire, Ohio, Pennsylvania, Oregon, Washington, West Virginia, and Wisconsin. Five of these states were decided by about 5 percentage points: (Maine for Gore; Michigan, Gore; Arkansas, Bush; Washington, Gore; West Virginia, Bush; and Arizona, Bush). Others were excruciatingly close. The winning margin in five states (Florida, New Mexico, Wisconsin, Iowa, and Oregon) was less than 1 percent. In most of Gallup’s recent polls in the battleground states, the race has been very close.

Battleground states are not necessarily swing states, as ABC News analyst David Morris reminds us: “From 1976 to 2000, Ohio and Michigan each had four Republican winners and three Democrats and Pennsylvania favored four Democrats and three Republicans.”

But other states that were close in 2000 don’t swing back and forth. Minnesota, which favored Gore over Bush by 2.4 points in 2000, has voted for Democrats seven straight times. Arizona has voted for a Democrat for president only twice since 1948.

Both campaigns will have roughly equal resources. And although the Bush-Cheney team has been perfecting a state-of-the-art, turn-out-the-vote effort, the Democrats and their allies will certainly be competitive. The election appears to be close because we have a closely divided country. Absent events, it’s likely to stay that way until people really start thinking about the contest in the fall.