Money in politics is a lot like water -- it tends to pool up in the lowest places. In an election year, traditionally, politicians like nothing better than a contract fight over garbage hauling, or cable franchises, or casino licenses. That's when the campaign donations really start flying, when business executives think they can get a leg up by writing a few checks.

You may have heard that there's an election for mayor in Philadelphia this year. It's been hard to find A-list candidates, for sure -- but it's even harder to find the money. Through the end of last year, the leading four candidates had raised just 1/8th -- 1/8th!!! -- of what the Top 4 candidates had raised in 2007. But now, new, stealthier sources of money are emerging.

The new funding sources share a common bond...charter schools. That's right, educating Philadelphia's kids is essentially the new slots parlors of the 2015 race for mayor. If that's not a metaphor, I don't know what is.

This isn't a total surprise. One of the candidates in the race, after all, is state Sen. Anthony Williams, who ran for governor in 2010 and received a staggering $5 million-plus from just three donors, the gazillionaire partners in a Bala Cynwyd-based hedge fund called the Susquehanna International Group. (He still didn't win, obviously.) The donors were pretty clear this was all about one single issue: Williams' enthusiastic and fairly unqualified support of charters, newer non-traditional schools that get our tax dollars to educate students.

Unlike state elections, Philadelphia has limits on donations, and so these three rich dudes can't give Williams more than a (relatively) puny $2,900 each in 2015. But in the new Wild West of unlimited campaign funding called "independent expenditures" -- the broad avenue plowed by the U.S. Supreme Court in the Citizens United case -- many looked for the hedge funders to find some way to invest -- and tnow that's a reality. On Monday, WHYY's Dave Davies reported that the Bala Cynwyders have formed and largely funded -- to the tune of $250,000, with presumably more to come -- a group called American Cities that will back Williams.

But that's not all. Today, Philly.com's Ryan Briggs uncovered two more political action committees (PACs) with ties to the charter-school movement. One, the Believe Again PAC -- linked to a local network of charter-school advocates although currently chaired (and this boggles my mind) by the top government liaison for the School District of Philadelphia -- has raised $114,000 so far.. The second, Leadership for Education Equity, which just registered to operate as a PAC in Philadelphia, is closely tied to wealthy backers of Teach for America, the teacher corps that started with good intentions but has evolved into something of a "school reform" cult (...which for some strange reason now needs a PAC!)

These groups are likely to easily pump 7-figures into the race by May -- and that could be enough to tip the election and ensure the next mayor is an enthusiastic backer of charters. Indeed, the School Reform Commission is under growing pressure to approve dozens of new charter-school applications, a decision that would speed the flow of students -- and tax dollars -- away from the collapsing traditional public schools. Already, instead of a concerted effort to improve education for all, the current chaos has become a free-for-all in which the Left Behind are attending schools without libraries or nurses -- a national embarrassment that has undercut Philadelphia's claims as a rising world-class city. Today's $35 million pledge from the Philadelphia School Partnership is a band-aid -- not the long-term equity that the city's kids deserve.

Wealthy folks seem energized about supporting charter schools for a variety of reasons. Some -- and the Bala guys are said to be in this category -- feel that school choice comports with their libertarian or free-market philosophy; others get involved in the charter game because they see kids as a "profit deal." Either way, TV ads about the mayoral hopefuls paid for by these school-choice aficionados are coming to a 6 p.m. newscast near you, soon. It's not clear if or how the one possible countervailing force -- the teachers' union -- will get involved. The one group I can guarantee you won't see is the Kids Without a School Nurse PAC. All they have is their protest signs -- and their parents' votes. Will that be enough?