If John F. Kerry's ad-buying strategy could be crystallized in a single phrase, it would be "Judge Judy." In President Bush's case, it's "Cops."

Backed by record-breaking expenditures for TV advertising, the presidential campaigns this fall are pursuing intricate strategies to target would-be supporters via the programs they watch. While much attention has focused on creating the right advertising message, the medium is important, too. As a result, both campaigns, and their allied groups, have been tweaking the lists of programs they sponsor in order to put their ads before select groups of voters.

For example, "Judge Judy" -- a nonfiction program featuring a strong-willed judge who tries simulated cases -- is a daytime show that appeals to a group of viewers Kerry's campaign is counting on: middle-aged women, both single and stay-at-home moms. To appeal to this group, Kerry has also run thousands of ads on such daytime staples as "Oprah," "Dr. Phil" and "Live with Regis and Kelly."

At the same time, Bush is attempting to shore up his base of support among younger and middle-aged white men. Thus, viewers in several states are likely to see ads for the president on such testosterone-fueled shows as "America's Most Wanted" and "Cops," on the Golf Channel, and during NASCAR races.

The rest of the time, the two campaigns' program-buying strategies overlap. From dawn to dusk, they battle it out during commercial breaks in "informational" programs such as "The Today Show," "Good Morning America" and the 6 p.m. local news, according to independent analyses of campaign ad-buying patterns. The other common ground is "Jeopardy" and "Wheel of Fortune," two widely syndicated programs that appeal to older viewers, who tend to vote in higher numbers than other demographic groups.

With five weeks to go, the 2004 campaign already ranks as the most expensive and most advertising-intensive in history. Ad expenditures by the Bush and Kerry campaigns through mid-September topped $300 million, surpassing the 2000 race's total by at least $100 million, estimates TNSMI/Campaign Media Analysis Group, a private tracking firm in Arlington.

The 2004 total does not include spending by independent groups. The Media Fund and MoveOn.org alone have spent about $50 million on anti-Bush ads in many of the same markets as Kerry, and often when his advertising was temporarily off the air.

The ad wars have gone on longer, too. In 2000, Bush and Al Gore did not begin advertising in earnest until June. This year, with Kerry having sewn up the Democratic nomination early, both candidates began crowding onto television in March.

The result is an unprecedented advertising pileup. Between early March and Sept. 21, the campaigns and independent groups have broadcast more than 600,000 spots about the candidates or the election, according to Kenneth Goldstein, a political science professor who directs the University of Wisconsin's Advertising Project.

The buying patterns suggest this may be the narrowest presidential ad campaign ever, with the nation split between ad haves and have-nots. Depending on the week, presidential commercials are running in only about 12 to 20 states, while most other states are in a virtual ad lockout. You won't see much in Washington, but it is raining commercials in Toledo, Tampa and Charleston, W.Va.

"If you live in any market in Pennsylvania, Ohio or Florida, you're guaranteed to see ads," says Evan Tracey, chief operating officer of Campaign Media Analysis Group.

The University of Wisconsin and Nielsen Monitor-Plus tracked an astonishing 501,259 ads (from both the presidential campaigns and allied groups) through the end of August and found that they had aired in only 100 of the nation's 212 media markets. Goldstein estimates that about 60 percent of the electorate has yet to see a campaign ad this year.

During September, he said, the ad field narrowed further. Kerry's campaign has moved ad money out of states once deemed competitive (Arkansas, Virginia, North Carolina, Missouri, Arizona and Colorado), but for now considered in Bush's column.

The shifting state-by-state and city-by-city strategies essentially affirm something that became apparent in 2000: the death of the national campaign ad. No longer does the country see the same political message simultaneously, as it did for decades until the Bush-Gore race, when the practice stopped.

"They're simply not cost-efficient anymore," says Kathleen Hall Jamieson, director of the Annenberg Public Policy Center. "There's no reason to spend money to [address] half the country when you're not campaigning in half the country."

The candidates still buy ads on cable networks, but Jamieson points out that audiences for cable channels are a fraction of those of the four leading broadcast networks: NBC, CBS, ABC and Fox. What's more, about 15 percent of the country cannot get cable or satellite TV. And while about two-thirds of American homes have access to the Internet, it is not clear how many people have watched a campaign ad over a computer.

The polarization of the electorate into "red" and "blue" states has in many ways helped the campaigns map their ad buying. Because a limited number of states are deemed "in play," both campaigns concentrate their resources on relatively fewer lower-cost locales. The ad battle is being contested outside eight of the 10 largest markets -- New York, Los Angeles, Chicago, Washington, San Francisco, Boston, Dallas and Houston. Only Philadelphia and Detroit, among the largest markets, have seen sustained advertising.

The Bush and Kerry campaigns declined to discuss their media-buying strategies in detail. But the outlines of their efforts have been apparent for months through tracking services such as TNSMI and Nielsen Monitor-Plus, an arm of the company that does the daily TV ratings.

Campaign media buyers use internal polling research and Nielsen's audience data to figure out where and when to direct their ads. The political ad buyer's world is circumscribed by three essential questions: Who is the advertiser trying to reach? Where do these people live? And what is the most cost-effective time and program to get your message in front of them?

For the most part during an election, two of the answers are easy: older people and informational programs.

"When you're promoting a product like beer or soft drinks or fast food, you're looking for a younger demographic," said Bill Carrick, a veteran Democratic media strategist who most recently advised Rep. Richard A. Gephardt (Mo.). "But a political campaign is almost universally [aimed at] audiences over 35."

By and large, this means buying time on news shows. It helps, Carrick says, that older people watch a lot of television, making them among the easiest-to-reach segments of the electorate. Finding and targeting younger, undecided voters is much tougher. "The very fact that they're undecided usually means they tend to be low on information," he said, "so they're not watching information-oriented shows."

Media buyers think in "dayparts" -- the industry term for the time of day and the type of viewers who tend to watch during those hours. For example, during daytime hours (between 9 a.m. to 4 p.m.) -- a daypart of soap operas, game shows and talk shows such as "Oprah" -- audiences tend to be older, less educated, more downscale and more female.

The late-night audience (11 p.m. to 1 a.m.) skews toward younger crowds, and audiences during "prime access" (7 to 8 p.m.) are typically elderly. Prime time (8 to 11 p.m.) offers the broadest possible audience, but it is also the most expensive daypart, which means it usually commands only about 20 percent of a campaign's TV budget, said Jon Hutchens, a Denver media specialist who is buying airtime for MoveOn, the Media Fund and the AFL-CIO.

Presidential candidates typically pay media buyers 7 to 15 percent of the cost of the airtime they purchase, but this is negotiable and the job is sometimes done on a straight-fee basis.

The Kerry campaign has put a greater emphasis than Bush's on younger and more urban audiences, Tracey said. Kerry has run ads on programs carried by stations affiliated with the WB and UPN networks -- which have younger viewers than affiliates of the major broadcast networks -- and on cable's BET.

As for Bush, says Tracey, his campaign has been an active advertiser on programs with gritty subject matter, such as "NYPD Blue," "Law & Order" and "JAG" -- all of which tend to have a strong appeal to men.

The question, though, is that with so much advertising directed at so few, how much is too much?

Media buyers tend to turn that question around: How can one side stay silent when the other is shouting? They say they must hammer home the message more times now because of the clutter of competing messages and demands for viewers' attention.

In addition to the candidates and the independent groups, the Democratic National Committee and Republican National Committee have media-buying operations, as do the parties' Senate and congressional campaign committees.

"Clutter has a mitigating effect on the effectiveness of any one ad," Hutchens acknowledges. "We're all pretty much selling the same stuff -- education, homeland security, health care. If you're in a hot market, you have a lot of [political organizations] talking about the same things."