Plenty of hopefuls for elected office in the District have argued that the city’s political system is rotten to the core, with the well-heeled and well-connected funneling vast sums of money to incumbents through all sorts of channels. Today’s news of a broadening investigation dating back to 2003 certainly won’t disabuse them of that notion.

NBC4 reports that the U.S. Attorney for the District has issued subpoenas to elected officials and candidates who received campaign contributions from businessman Jeffrey Thompson or individuals and institutions connected to him dating back some eight years:

Sources say the subpoenas are going to any political campaigns since 2003 that may have done business with Thompson or accepted contributions from him or his associates.

Several council members confirmed they have received the grand jury subpoenas but declined further comment. Others said they have not received the mailed subpoenas but have heard about them.

Sources say the subpoenas are not limited to council members, but include candidates for mayor and other offices dating back to 2003.

Thompson is not only the city’s biggest contractor, but also one of its most prolific fundraisers. The City Paper reported last year that he had given over $730,000 to candidates for office over the last decade. A review of contributions recorded by the Office of Campaign Finance shows that Mayor Vince Gray, former Mayor Adrian Fenty, D.C. Council Chair Kwame Brown, and councilmembers Marion Barry (D-Ward 8), David Catania (I-At Large), Phil Mendelson (D-At Large), Jim Graham (D-Ward 1), Jack Evans (D-Ward 2), and Mary Cheh (D-Ward 3) received money directly from Thompson. A number of candidates were also beneficiaries of Thompson’s largesse—former D.C. Council Chair candidate Kathy Patterson and Republican Pat Mara. (Loose Lips has a picture of one of the subpoenas.)

But Thompson’s personal contributions aren’t the only issue—it’s also the money that came from individuals and institutions associated with him. Councilmember Vincent Orange (D-At Large) is currently facing questions regarding $26,000 in money orders he received last year from individuals tied to Thompson; the money helped Orange win the At-Large special election. Money orders aren’t illegal, but some say they can be used to conceal where money is actually coming from.

Last month, Thompson’s home and office were raided by federal officials.

The news will likely feed support for a movement that’s coalescing around a citizen-sponsored initiative to ban corporate contributions from D.C. campaigns. (It’s now known as Initiative 70, or “The Prohibition on Corporate Campaign Contributions Initiative of 2012.) The D.C. Board of Elections and Ethics today released the petitions to the public, and organizers have until July 9 to gather 22,942 valid signatures to get the measure on the November ballot.