Rep. Alcee Hastings (D-Fla.) grabbed the title of poorest Member of Congress in Roll Call’s annual survey of lawmakers’ wealth this year, thanks to decades-old legal bills he incurred in the 1980s defending charges that he had taken bribes as a federal judge in Florida.

The outstanding legal debt put Hastings’ net worth at about negative $2.13 million in 2010 — unchanged from the year before — though the Congressman’s legal liabilities could run as high as about $7.3 million. A jury acquitted Hastings, but he was ultimately impeached and convicted by Congress.

Though Hastings is a list stalwart, the group that makes up the least wealthy in Congress is not static.

Last year’s poorest lawmaker on paper, Sen. Herb Kohl, landed squarely among the list of Congress’ wealthiest this year. Though the overall value of the Wisconsin Democrat’s assets dropped precipitously due to an asset transfer to a blind trust, the liabilities of the Milwaukee Bucks, the NBA team owned by Kohl, dropped in relation to the team’s value, boosting the overall wealth reported on the well-off lawmaker’s financial disclosure.

Though Rep. Louie Gohmert (R-Texas) listed no assets and personal and consolidated student loan debts for his children worth at least $100,000 on his 2010 financial disclosure, he was pushed off the list of the poorest in Congress this year by lawmakers with a higher debt-to-asset ratio.

Each year since 1990, Roll Call has reviewed the financial disclosures of all House and Senate lawmakers to determine the 50 richest Members of Congress for an annual report. To calculate a Member’s minimum net worth, Roll Call adds the minimum value of all assets and subtracts the total minimum value of all liabilities.

The reports provide a picture of Members’ assets and liabilities, but the annual financial disclosures are an incomplete account of individual wealth. Though Members report assets such as bank accounts, stocks and rental properties, they are not required to disclose the value of personal homes or federal retirement savings accounts. Student loans and credit card debts appear as liabilities but mortgages related to a primary residence, for example, do not.

Other Members on this year’s list of the least wealthy are there partly because of debts associated with legal problems.

Rep. Laura Richardson (D-Calif.) has at least $150,000 in outstanding legal bills that contributed to a net worth of negative $269,000. Rep. Sanford Bishop (D-Ga.) owes a $250,000 debt to the law firm Greenberg Traurig. The outstanding legal fees are believed to be related to when the Georgia Bureau of Investigation probed a local youth program that had received hundreds of thousands of dollars in federal earmarks from Bishop and had hired the lawmaker’s stepdaughter and her husband. The bureau later determined that no wrongdoing had occurred.

Other lawmakers that rounded out the list of the least wealthy in 2010 included Reps. Rubén Hinojosa (D-Texas), Barbara Lee (D-Calif.), John Sullivan (R-Okla.), Jerrold Nadler (D-N.Y.), Linda Sánchez (D-Calif.), Sean Duffy (R-Wis.) and Kristi Noem (R-S.D.).

Because of the way financial details are reported on the annual disclosure form, which asks for the year-end value of assets but liabilities that exceed $10,000 at any point during the calendar year, some lawmakers are likely to drop off the list of the poorest once recently paid-off loans and mortgages are no longer reported.

Sánchez, for example, sold a property last year in D.C., but the mortgage was still included on her financial disclosure form. Nadler paid off a student loan in May 2010 of at least $250,000 that was recorded as a liability for that year but will not appear on his 2011 filing. Sullivan sold a rental home but still reported a mortgage of at least $500,000 on the property that will likewise not be among the liabilities he reports in subsequent filings.

See the chart of the 10 poorest Members.