Four years ago, President Clinton helped open the floodgates for a new form of political advertising, persuading the Democratic Party to spend millions of dollars on early TV spots boosting his reelection. This week, his wife became the first--and so far, only--Senate candidate of 2000 to benefit from such spending.

With an infusion of $100,000 from the Democratic Senatorial Campaign Committee, New York state Democrats announced a new ad campaign urging voters in upstate New York to "call Hillary" and support "leadership that's on our side." The spots are meant to answer a preemptive television strike last week by Clinton's expected GOP rival, New York City Mayor Rudolph W. Giuliani.

But while the mayor is funding his ads directly from his own campaign account, the first lady is getting a crucial assist paid for wholly by the party.

"We picked up the entire tab," said DSCC political director Jim Jordan. "The Democratic Party in New York felt strongly that going on the air now would be helpful in the long run to Mrs. Clinton and they made a convincing case to us."

In an ironic reprise of a legal debate first raised by President Clinton's own involvement in the 1996 Democratic Party ads, Republicans in Hillary Clinton's adopted home state said yesterday they are considering filing a complaint with the Federal Election Commission alleging that the state party improperly coordinated the ads with her campaign.

At the same time, the Senate campaign committee's decision to pay for the new round of ads touting the first lady has resurrected questions about whether her celebrity candidacy will draw party resources away from other Democratic Senate contenders. Democrats point out that she has also raised significant funds for the DSCC this year, but acknowledge that the party's spending allows her to conserve more of her own campaign war chest for next year's contest.

Because they stop short of urging viewers to vote for Clinton, the ads can be paid for by the party in part with unlimited "soft money" contributions from wealthy individuals, corporations and labor unions. Yesterday, top Clinton strategists defended the use of the ads--and said it was perfectly appropriate for them to discuss the spots with the state party.

"It was done in '95, in '96, and it will be done this year," said Harold M. Ickes, who as White House deputy chief of staff coordinated the president's 1996 reelection campaign with the Democratic National Committee and is now a top adviser to Hillary Clinton's Senate bid. "It's perfectly legal and kosher."

While Giuliani is paying for his spots with his campaign funds, Ickes said, "We're not dictated by what he does." He added that the Clinton team, which sources said has already raised several million dollars, has no plans to use any of it soon on advertising: "We don't need to be spending money at this point."

Republicans have focused their complaints on the question of alleged coordination between Clinton aides and the state Democratic Party chair, Judith Hope. Hope told reporters on Tuesday that the ads were her idea, but she acknowledged that she discussed them with the first lady herself as well as her campaign advisers.

Ickes yesterday acknowledged that he had spoken with Hope and had given what other Democrats characterized as "advice and counsel." David Axelrod, the media consultant who made the spot, said Hope called him about a week ago and asked him to make the ad. His media firm even paid the campaign for the footage of Hillary Clinton he used, Axelrod said, to make sure the state party was not improperly using campaign resources.

But the state GOP argues that the admitted consultation between Hope and the Clinton campaign may have crossed the legal line.

Benjamin L. Ginsberg, a GOP election lawyer advising the state Republicans, said a recent federal court decision in a case involving the Christian Coalition suggests that coordination with campaigns on such ads may not be appropriate.

But several other election law experts said the GOP complaint was unlikely to succeed--in large part because of the example set by President Clinton in 1996--and ultimately followed by his GOP rival, Robert J. Dole.

"The FEC specifically declined to proceed further regarding the 1996 DNC ads. It was very clear that Bill Clinton had written the ads, but the whole idea was the FEC had never promulgated proper rules and regulations to govern this kind of advertising," said Republican election lawyer Cleta Mitchell.

Mitchell said the ads highlighted Democratic hypocrisy about soft money, rather than questionable legality. "Democrats say on the Senate floor that they want to get rid of soft money," she said. "Well, this is what soft money does--it buys ads. If they want to get rid of it, they're being very hypocritical to spend this money."

The early-starting New York air war is the first in any Senate race in the country. Stuart Roy, a spokesman for the National Republican Senatorial Committee, said the GOP does not plan to spend any money on issue ads boosting its candidates until "well into next year." Roy also argued that the Democratic ads are a sign of how distracting Clinton's candidacy will be to the party's other campaigns next year.

"She's going to siphon off attention and money that might otherwise go to other candidates," he said. "Instead, it's going to be spent in New York--and this is a pretty good example of it."

But Democratic officials insisted that the new ads were not a sign of favoritism to Clinton, citing her strong fund-raising on behalf of the party. "Make no mistake," the DSCC's Jordan said, "she is a net financial benefit to the Democratic Party, to this committee, and to other candidates."

While it is illegal for candidates to raise money for the party directly earmarked for their own campaigns, many Senate contenders solicit funds for the DSCC that ultimately help their races. "It's fair to say that more than $100,000"--the cost of the ads--"has been raised by her efforts for the DSCC," Ickes said.

CAPTION: First lady Hillary Rodham Clinton is focus of ads funded by Democratic Senatorial Campaign Committee.