What's that they say?

Money isn't everything.

Given the new politics of Philadelphia, it's at least possible to conclude that money isn't the only thing anymore.

That's a major achievement, considering the city's corrosive, pay-to-play political culture. All of the credit goes to the now battle-tested campaign-finance limits, which had their first tour of duty in this week's Democratic mayoral primary.

The success of the city's caps on donations in this election is the best reason to leave them in place.

Look no further than the losing candidacy that triggered a scramble among City Hall veterans to scrap the most far-reaching campaign reform in decades: Nearly $10 million spent by first-timer Tom Knox purchased plenty of television time, but not enough to mask Knox's shortcomings as a mayoral contender.

At the same time, the annual limits on donations - adjusted upward, due to Knox's personal spending, to $5,000 per person and $20,000 per political committee - shaped one of this city's most deliberative and issues-based mayoral races.

Candidates, denied the unlimited resources of past mayoral contests, got out their message, in part, by trekking to one citizen forum after another. That also meant they were challenged to confront a range of issues, not just those that fit neatly in a campaign TV-ad strategy.

For Democratic mayoral nominee Michael Nutter, the donor limits were a symbol of his reform candidacy and proof of his advocacy for change while serving on City Council.

As a councilman, Nutter championed the limits - in a telling contrast with the current mayor. As a candidate, Nutter lived within the limits, yet still managed to raise the millions he needed to win over a solid block of voters.

The donor limits forced Nutter and the three other mayoral hopefuls who did not have Knox's fortune to get support from thousands of people, not just a moneyed few.

That means a Nutter administration will be under less pressure from donors who would expect city policy or contracts crafted to their liking.

Asking candidates to raise money in smaller chunks also tested their mettle. Nutter spent four to five hours a day dialing for donors, demonstrating doggedness and a stellar work ethic.

A challenge to the campaign limits remains before the state Supreme Court. But the state's Commonwealth Court judges - and now Philadelphia voters - have ruled that the limits should stay.