THE PARADE of Philadelphia politicians in trouble with the law seems to grow larger each passing month.

Last week, state Reps. Ronald Waters and Vanessa Lowery Brown were charged with accepting bribes offered by a fake lobbyist as part of a sting operation.

District Attorney Seth Williams is continuing his investigation of two other state legislators about their possible involvement in taking money from the same "lobbyist."

Last month, state Sen. LeAnna Washington pleaded guilty to using her Senate office staff to raise money for her campaign. When one aide told her she was violating state law and the Senate rules, she famously replied: "I am the f---ing senator and I do what I want."

A week doesn't go by without one or another former Traffic Court judge appearing before a federal judge to be sentenced for their roles in a ticket-fixing scheme. A total of six ex-judges face sentencing, and most so far have gotten jail terms.

Meanwhile, a federal investigation continues into U.S. Rep. Chaka Fattah for an alleged scheme to illegally pump money into his 2007 mayoral campaign. Two close Fattah aides have already pleaded guilty to charges related to the money-laundering operation. Obviously, there is more to come in this case.

There's something important to keep in mind about all of these cases.

All of those listed above are members in good standing of the Democratic political organization that has had a hammerlock on political power in the city for decades.

Take those Traffic Court judges as an example.

They didn't get together over coffee one day and decide on the spur of the moment to run what one investigator called a "two-track system of justice, one for the politically connected and another for the unwitting general public."

Most of these judges were elected to their positions as pure party people. They were ward leaders or friends of ward leaders and certainly well-connected within the party. That's how they got endorsed by Democratic City Committee.

They didn't buck the organization when they fixed those tickets. They acted as agents of that organization.

Waters and Brown certainly weren't acting as agents of the party when they took bribes. They took the money for themselves. It was a petty act of greed. Still, they were abusing their power as elected officials.

One of the roots of that abuse - or arrogance, in Washington's case - stems from the fact that they have safe seats. With few exceptions, once elected to public office in this town you can hold it for life.

Washington is one of those exceptions. She lost in this year's Democratic primary - to a strong candidate, Art Haywood, from the Montgomery County portion of the district. At the time, she was under indictment.

We, the unwitting public in Philadelphia, haven't done ourselves a favor by handing so much power to the Democratic Party and, particularly for less-visible offices, to the party organization.

Without a viable Republican Party in town, without a cadre of strong dissidents within the Democratic Party, we voters tend to sail along, unthinkingly sending the same-old, same-olds back to power.

What we are seeing in these cases is a certain arrogance and smugness that comes from holding power for so long.

As a historian once noted, power tends to corrupt and absolute power corrupts absolutely.

Without any competition at the voting booth, the only agents of change left in Philadelphia politics are local, state and federal prosecutors.