DES MOINES - Iowans bombarded by presidential politics during the state's first-in-the-nation caucuses now find themselves in the middle of a political battleground both Democrats and Republicans vow to conquer in the campaign to win the White House.

Iowa has shaped up as one of 16 or 17 "battleground" states, depending on who is counting, that could swing to either Republican President George Bush or presumptive Democratic nominee John Kerry this November.

Even though Iowa voters backed the Democratic candidate in the last four presidential elections, the state is as narrowly divided as the rest of the country after the cliffhanger 2000 election between Bush and Democrat Al Gore.

That race split the country into what is commonly known as the "red states" that will presumably back Bush in November, and the "blue states" that will likely throw their support behind Kerry.

In the middle are Iowa and a handful of states both campaigns see as theirs to capture.

"It's about the margin," said Jennifer Duffy, an analyst with The Cook Political Report in Washington D.C. "The red states are pretty red; the blue states are pretty blue, so it's not an efficient use of time or resources for the campaigns to try to change that part of the map," Duffy said.

That means Iowans will have a front-row seat for Campaign 2004 and will be blitzed by television ads, phone calls, direct mail and visits from the candidates and their surrogates.

"I think the voters of Iowa and the other states that make up the battleground will certainly be making an educated decision. There's not much they are going to miss," Duffy said.

Iowa's elevated status has been evident in the last month with visits from both candidates. Bush came to Des Moines on April 15, and sources say he will return to Dubuque Friday as part of a battleground state bus tour through the Midwest.

Last week, Kerry made his first visit to Iowa after winning the caucuses in January to thank Democrats for giving him early momentum in the primary contest.

The inclusion of Democratic Gov. Tom Vilsack in the vice-presidential sweepstakes is only adding to campaign hype in Iowa. Vilsack has been frequently placed on a short list of potential running mates for Kerry, although the governor tries to downplay his chances.

Steffen Schmidt, a political science professor at Iowa State University, said the 2000 election showed candidates must be competitive in more than just states with a large number of electoral votes such as California and New York.

The 2000 election illustrated the importance of states that are narrowly split, including Iowa, where Democrat Al Gore won the state and its seven electoral votes by a mere 4,144 votes.

"It's clearly a state that has tightened up, a state that is very, very competitive in terms of the parties," Schmidt said.

At last count, the number of registered Republican voters in Iowa sat at 617,031, while the number of Democratic voters was close behind at 604,612. A larger share, or 781,770 voters, are not registered with either party, according to figures from the Secretary of State's office.

Iowa Democratic Party chairman Gordon Fischer believes the caucuses energized Democrats and allowed them to update voter lists, which he said will give Democrats a "terrific organizational advantage" in the fall.

During the caucus season, the party registered close to 18,000 new voters and about 35,000 Republicans and independents switched their party registration to Democrat, according to Fischer.

He discounts the idea Iowa is a battleground state, but admits the vote here is likely to be close.

"I don't think that we're a toss-up state. I think we lean Democratic, but that doesn't mean we're not going to have to fight for every vote," Fischer said.

Former Iowa GOP chairman Steve Grubbs of Davenport said although the state is usually not that important after the caucuses, polling shows Iowa is "absolutely a battleground state in every way" this year.

He doubts Democrats have a strategic advantage simply because they hosted the first primary contest in the nation.

Iowa Republicans wrongly assumed they had a November advantage to hand to Bob Dole after he won the Iowa caucuses in 1996, Grubbs said.

"It didn't help us in '96 and it won't help them in 2004. What will matter is who voters think is the best person to lead the economy of the United States," Grubbs said.

Most say the state of the American economy will be the key issue in Iowa and other battleground states like Ohio and Michigan that make up the country's industrial heartland.

Kerry used the primary season to underscore the loss of American manufacturing jobs under Bush's watch, and last week laid out a plan to revitalize the manufacturing sector.

But the Bush campaign and Republican-backed groups arguably have had success with television ads that depict Kerry as a president who would raise taxes and increase the deficit.

Duffy, the Washington, D.C., political analyst, said those ads have been effective in raising questions about Kerry, despite the candidate's claims they are untrue.

She said Republicans will also try to rob Kerry of credibility on foreign policy issues and his ideas on the direction the U.S. should take in the war in Iraq.

While voters in other states considered securely in Bush or Kerry's column may not see many presidential campaign ads, TV viewers in the battleground states already have had an early look at the fall campaign through campaign commercials.

"If you live in one of these 16 states, it looks like this campaign is fully engaged," Duffy said.