See the large blue portion in Mississippi? That's Bennie Thompson's district. When he was first elected to Congress in 1993, he was essentially broke. Now,he's worth over 20 million dollars.
In the meantime, the rest of his district is the most poverty-stricken in the U.S. You take away Bennie Thompson's district, Mississippi ranks 20th-30th in all pertinent categories (education, income, teenaged pregnancies, obesity, etc.).