Over the past 18 months, Pennsylvania voters have painfully detached quite a few leeches who'd spent years sucking the life from the body politic. As much success as we've had, the constant news stream of Harrisburg corruption demonstrates that we still have some messy work to do.

Leeches use a combination of mucus and suction to attach to a host, but they naturally fall off once they're full. No such built-in stopping point has been observed in the human variety of leech.

These slimy suckers ply the corridors of political power around the country, but Harrisburg is renowned for its high concentration of the species. The challenge for voters concerned with the commonwealth's wellbeing is that the leeches, like the true public servants, wear suits.

Figuring out who's who, or which is which, and removing the stubborn parasites will require our attention and cooperation all the way through the next election cycle. Luckily for us voters, the process is proving to be pretty entertaining.

This is the point in a column where a writer gauges her metaphor carefully to make sure that its too-frequent use does not constrain the presentation of facts. Happily for this writer, and sadly for us voters, the leech metaphor just keeps giving and giving and giving because -- you saw it coming -- the leeches just keep taking.

The moment we the people realized we were being drained of too much life-force too fast was the July 2005 pay raise, of course. But before that bipartisan stealth maneuver, our elected representatives had long enjoyed unfettered access to constant streams of nourishment in the form of cash.

Scientists say that leeches release an anaesthetic to dull their host's senses and remain undetected. Something similar must have happened to Pennsylvania voters, because our leaders have been sucking up generous per diems, free meals, leased vehicles, full health insurance and lobbyists' favors for years, all without our minding.

Leeches also secrete an anti-clotting enzyme into the host's blood stream to make sure the flow doesn't stop. Similarly, our solons saw to it that pesky paperwork would not interfere with their cash supply. They didn't have to file receipts to claim their per diems, and they strictly limited reporters' and constituents' access to the slush fund expenditures that they did have to document.

Our elected officials took all this, and we didn't utter a peep of protest. But the pay raise? We felt that.

The leeches structured the pay raise with the same "unvouchered" anti-clotting technique that had proved successful for so long. No expert has been able to satisfactorily explain why it didn't work this time.

We the people have been plucking the parasites off the body politic ever since. We removed some during the primaries and some in the November elections. Others, we're learning, still need to go. Prying them off may require criminal indictments.

The biggest flow in Harrisburg these days is the flow of incriminating information on how much some elected officials have taken. Allegations that state Sen. Vince Fumo, D-Philadelphia, used public employees as housekeepers, chauffeurs, construction managers and personal obstructers of justice are among many crimes listed in a federal indictment last week.

Reformers are asking the state attorney general to investigate the big jump in bonuses paid to Harrisburg staffers in 2006, an election year. Reporters plowing through the reluctantly released documents have already uncovered a high correlation between those who did campaign work for embattled politicos and those who got handsome bonuses.

Surprisingly, even our representatives' potentially illegal bonuses for up-and-coming workers of the Harrisburg spoils system fits the leech metaphor. Scientists have noted that some species of leech nurture their young, according to an online encyclopedia, "providing food, transport, and protection, which is unusual behavior in an invertebrate." They're spineless, but they take care of their own, just like our "leaders"!

As previously noted, while true leeches stop sucking when they're full and fall off their host to digest their meal, their human counterparts don't do this. In fact, the Fumo indictment seems to indicate there's no such thing as "full."

Wiser or more cowardly lawmakers, however, did voluntarily stop active feeding before being removed through the electoral process. They'll be digesting generous pensions for a long time.

Reformers like Gene Stilp had been trying to call attention to this abuse for years before the 2005 pay raise roused the rest of us from our stupor. We've elected a critical mass of new thinkers to work inside the system, and outside agents, known as "prosecutors," are lending a hand.

A few former leeches have even got reformers' religion and morphed into something that stands a little more upright. But the evidence indicates that whether it's addressed in the courts or at the ballot box, the bloodletting isn't quite done.