American Bankers Assn.

Representing banks of all sizes, it spent more than $6.2 million on lobbying in 2010

Financial Services Roundtable

Lobbyists for banks and nonbank financial companies with $92.7 trillion in total assets, including Bank of America (BAC), General Electric (GE), and Wells Fargo (WFC)

National Association of Realtors

A trade group with 1.1 million members, its political action committee contributed $3.9 million during the 2010 midterm election cycle, more than any other PAC

National Association of Homebuilders

A Republican-leaning federation that helped House Financial Services Committee Chairman Spencer Bachus (R-Ala.) raise nearly $200,000 from the housing industry, the top donor to his 2010 reelection campaign

National Fair Housing Alliance

Steers a coalition of more than 20 civil-rights groups, including the NAACP, in an effort to preserve access to fair credit and homeownership

National Council of State Housing Agencies

These state government boards have more than $115 billion in bonds outstanding to aid first-time home buyers. They plan a lobbying campaign in March to highlight who benefits from low-cost mortgages

Data: Bloomberg, Center for Responsive Politics