Congressman Geoff Davis, a Republican serving Kentucky's 4th congressional district, announced in 2011 that he was retiring from office at the end of his term, but in the summer of 2012, Davis resigned his seat immediately.
A scandal broke out shortly after Senator Barack Obama was elected President in 2008. It involved the then-governor of his home state and the Senate seat that the President-Elect was vacating. Then-Illinois Governor Rod Blagojevich was caught trying to sell Obama's vacated Senate seat. He even tried to enlist the assistance of the incoming administration, which evidence pointed out that it quickly declined to do. Blagojevich wanted something for that seat.
Imagine a congressional district as a community. It has about 700,000 people, including a fair number of infants, and a few folks who've lived for more than a century.