You may want to first try the Office of Personnel Management website (
www.opm.gov) as most jobs in DC are federal and they have a pretty complete list. You can also submit a federal application through that site. I don't know for sure, but I would guess that political appointments aren't covered by OPM and your best bet for obtaining a job with a politician would be to go through your Congressman or Senator's local offices to see if they in fact, do need help in DC. They may even take your resume through the local office.
Just a word--secretarial positions such as the kind you're looking for with regard to judges (and I'm assuming you're talking federal judges) won't be easy to come by.
Don't limit yourself to politicians and judges--I'm sure there's plenty of Executive Assistant-type jobs there. Also be aware that they're probably not called that as each agency has different job descriptions and titles.
Good luck!
Karen