WASHINGTON (AP) _ Sen. Kent Conrad's home state of North Dakota has only 600,000 people. But his seat on a key committee has made the state the center of attention in the nation's debate over health care reform.

At least a half-dozen groups on all sides of the issue have bought thousands of dollars worth of newspaper, television and radio ads in North Dakota and a handful of other states with swing votes in the Senate.

Conrad, a moderate Democrat, is a member of the pivotal Senate Finance Committee. He's up for re-election this year and he's considered influential with other senators, including North Dakota's other senator, Byron Dorgan, also a Democrat.

''It's important to go duck-hunting where the ducks are,'' said Brent Bahler, a spokesman for Citizens for a Sound Economy, an anti-tax group that is running radio ads in North Dakota attacking the Democratic health plans.

The ad urges listeners to ''get on the horn to Senator Conrad and tell him that a Clinton-like plan for government-controlled health care is a risk we just can't afford.''

The group has bought air time for similar ads in Oklahoma, New Jersey, Louisiana and Nebraska.

On the other side, the Health Care Reform Project has bought newspaper and radio advertisements attacking the Pizza Hut restaurant chain for opposing employer-paid health insurance, something it provides its workers overseas.

''No matter how you slice it ... Pizza Hut does not deliver the same health benefits in America as it does in Germany and Japan,'' said an ad that ran in the Bismarck Tribune on Tuesday. The ad listed Conrad's and Dorgan's telephone numbers.

Other groups that have bought ads in the state include the National Restaurant Association and the Healthcare Leadership Council, a group of health industry executives.

''If we can make something happen with Conrad, it's worth perhaps three or four votes in Senate,'' said Dan Dougherty, a field worker for the Health Care Reform Project, an organization of unions, large companies and health care providers.

The group, which sent Dougherty to the state to organize pressure on Conrad, wants Congress to guarantee health insurance to everyone and require employers to provide it.

''How I view my object here is to try to create a climate where the senator is emboldened to come out for those two positions, something that has been hard for him to do in this environment since the first of the year,'' Dougherty said.

Health care reform has never been as hot an issue in North Dakota as in some other states.

There is strong opposition to making employers pay, and 90 percent of North Dakotans already have health insurance. There is worry about the move nationally toward ''managed care'' plans that limit the choice of doctors and hospitals. Most North Dakotans are insured through a single company, Blue Cross-Blue Shield, which has no such restrictions.

Dorgan dismisses the media blitz as ''background noise.''

''People in North Dakota are very independent,'' Conrad said. ''They call and say what they want to talk about, not what some group is telling them to say.''