New York City has had plenty of experience dealing with the topic that the Philadelphia City Council will consider at a public hearing today:

How to adjust a campaign-finance system to handle a very wealthy mayoral candidate - Tom Knox in Philadelphia - who's willing to fund his own campaign.

New York's history with its current mayor, Michael Bloomberg, demonstrates there isn't all that much that can be done to adjust the tilt of the playing field when a multi-millionaire enters the fray.

"Self-financed candidates are the 800-pound gorillas in campaign finance today," said Rachel Leon, executive director of Common Cause in New York City. "No matter what you do, they're going to outspend the traditional candidates."

The New York experience also suggests that money isn't everything - there were other reasons why Bloomberg, a Republican, got elected in 2001 and reelected in 2005 - and that a lot of voters aren't offended by big spenders.

Of course, Tom Knox, a Democrat, isn't Michael Bloomberg, who's spent more getting elected mayor of New York than any American has ever spent getting elected for anything.

In his two victories, Bloomberg, a billionaire, used $159 million of his own money. Thus far, Knox has given his own campaign a mere $5 million, although he has expressed a willingness to give more.

Before Bloomberg decided that he wanted to run the nation's largest city, New York already had in place a model campaign-finance system.

As of 2001, the system included partial public financing for those candidates who agreed to accept spending restrictions. It also had limits on contributions - originally $4,500 per individual - and bonus money for candidates whenever a wealthy individual spent at least $3 million on his own behalf.

(The Philadelphia system, new for this election, has contribution limits but no public financing or spending rules.)

In 2001, the previously little-known Bloomberg chose not to participate, as was his right. He didn't need the public financing - a 4-1 match on contributions. So he didn't have to abide by the spending limits.

He wound up spending $74 million of his own money, narrowly defeating Democrat Mark Green, who raised and spent $16 million.

Obviously, Bloomberg's money helped. Without the television commercials they bought, his candidacy wouldn't have been credible. But other factors contributed to his winning.

Foremost among them was the 9/11 attack on the World Trade Center, which happened less than two months before Election Day and made the endorsement of Bloomberg by outgoing Mayor Rudolph Giuliani extremely valuable.

In the aftermath, New York revised the rules to give additional help to candidates not capable of self-financing.

So in 2005, once Bloomberg spent more than $17 million (on his way to $85 million), his Democratic rival, Fernando Ferrer, was allowed to spend as much as he wanted and was given a 6-1 match on what he raised.

None of it helped much. Bloomberg, by now a popular incumbent, outspent Ferrer by 9-1 and easily won a second term. There was little, if any, backlash to Bloomberg's spending.

"The public generally doesn't care," the mayor's campaign manager, Bill Cunningham, told a post-election conference in 2005, " . . . because they accepted the premise that if the mayor spent his own money, that he had made by himself, he didn't owe anybody anything."

Reformers in New York would like to do something more to make their system less prone to being overwhelmed by a rich person. But one idea that has not received significant support is that of doing away with all contribution limits whenever a multi-millionaire comes along.

Such an option is now before Philadelphia's City Council.

In fact, New York's Campaign Finance Board, in a post-mortem on the 2005 election, expressed concern that raising or eliminating the limit - now $4,950 there - "would invite the influence-seeking [or the appearance of it] that the program is intended to deter."

In Philadelphia's campaign-finance law, enacted in 2003, contribution limits were set at $2,500 per individual and $10,000 for political action committees. Under an amendment passed last year, those limits double whenever a candidate gives $250,000 to his own campaign, as Knox has done. Council is considering higher limits to correspond to higher spending by a self-financed candidate.

The underlying problem for lawmakers throughout the country is the U.S. Supreme Court's interpretation of the Constitution. In its 1976 Buckley v. Valeodecision, the court ruled that spending one's own money to get oneself elected amounts to speech and thus is protected by the First Amendment.

Contact senior writer Larry Eichel at 215-854-2415 or leichel@phillynews.com.