Can somebody tell me why this crook is still in Congress?

We Democrats believe in due process, unlike another party that I can think of. Still, haven't we learned enough about this guy?

Admitted Bribers Head to The Slammer... and Jefferson Waits
By Paul Kiel - February 26, 2007, 1:53 PM

On Thursday, two businessmen will head to prison for conspiring to bribe Rep. William Jefferson (D-LA). And Jefferson himself? He'll most likely be enjoying an indictment-free spring as his lawyers battle with prosecutors over documents seized from his congressional office last May.