After 74 Democratic members of the House of Representatives sent a letter to Federal Communications Commission Chairman Julius Genachowski warning that the FCC should not advance net neutrality rules without explicit direction from Congress, Free Press put together a page showing career campaign contributors from PACs, employees and lobbyists of interests that oppose the measure, intended to keep the Internet a level playing field.

The biggest recipient of telecom campaign cash was Rep. Bobby Rush, D-Ill., who took in more than $128,000–over the course of an 18-year career, that averages out to about $14,400 an election cycle. Four signers–Rep. Wally Minnick, D-Idaho, Rep. Tim Bishop, D-N.Y., Rep. Chris Carnes, D-Pa. and Rep. Edolphus Towns, D-N.Y.–are listed as “n/a.” They didn’t get any contributions from telecommunications industry individuals and PACs. Towns has been in the House since 1983, or ten years longer than Rush.

Looking at just the 2010 election cycle, a TransparencyData.com query using relevant telecommunications industry categories in Center for Responsive Politics data (rather than specific companies and their lobbyists fighting net neutrality that Free Press used) shows that the 74 signers averaged about $16,900 in campaign contributions; the rest of the Democratic House caucus averaged $16,300 from the same telecommunications interests.

Here’s a different data point: The 74 signers include 18 of the 39 members of the Congressional Black Caucus (Towns, for example, is a member). In 2004, the Center for Pubic Integrity looked at another issue that bothered some of the same companies that oppose net neutrality rules–a la carte cable service (in which consumers would choose which cable channels from a menu, rather than subscribe to a predetermined slate). Some members of the CBC opposed that measure too; investigative reporter John Dunbar found a pattern of letter writing, with multiple members using similar language to protest a la carte pricing, and pointed out the contributions from cable companies to the Congressional Black Caucus Foundation, which is affiliated with the caucus but a separate entity:

In its 2002 annual report, the foundation, which ranks donors within ranges, lists Time Warner (then AOL Time Warner) as contributing between $50,000 and $99,999. In the 2003 report, the company jumped a tier, contributing between $100,000 and $249,999. Comcast also upped its contribution, from between $30,000 and $49,999 in 2002 to between $50,000 and $99,999 in 2003.

Viacom companies are listed as contributing between $20,000 and $44,998 in 2002, but in 2003 only Viacom was listed as contributing between $5,000 and $14,999. The NCTA donated between $5,000 and $14,999 in 2002 and 2003.

In addition, Comcast, the NCTA, Time Warner and Viacom are all regular sponsors of the caucus’s annual legislative conference. In all, over the two years, those companies contributed as much as $589,991.

The New York Times reported on the caucus’ activities a while back:

The caucus says its nonprofit groups are intended to help disadvantaged African-Americans by providing scholarships and internships to students, researching policy and holding seminars on topics like healthy living.

But the bulk of the money has been spent on elaborate conventions that have become a high point of the Washington social season, as well as the headquarters building, golf outings by members of Congress and an annual visit to a Mississippi casino resort.

In 2008, the Congressional Black Caucus Foundation spent more on the caterer for its signature legislative dinner and conference — nearly $700,000 for an event one organizer called “Hollywood on the Potomac” — than it gave out in scholarships, federal tax records show.

Many of those interests still contribute to the foundation (Comcast and Verizon between $100,000 and $249,999; AT&T and Time Warner between $50,000 and $99,999).

Special interests in Washington have many levers to influence politicians; not all of them show up in FEC records, lobbying disclosure records or IRS forms 990s (filed by nonprofit groups like the Congressional Black Caucus Foundation). Disclosure still isn’t where it needs to be to truly follow the money.

(Full disclosure: Bill Allison used to work at the Center for Public Integrity, and edited Dunbar’s story.)