When Democrats gather in Denver later this month to nominate Barack Obama for president, one of the event’s main corporate sponsors will be AT&T, which will splash its brand all over the convention, right down to the 2008 Democratic National Convention totebags that will be given to all the delegates and credentialed media.

For progressives, who have watched with dismay this summer as the presumptive nominee staked out increasingly rightward positions on a number of issues, including immunity for telecoms that participated in President Bush’s domestic spying programs, the cozy partnership of Obama and the Democrats with AT&T is just one more thing to grind their teeth about.

“The Obama brand has always been about inspiration, a new kind of politics, the audacity of hope, and ‘change we can believe in,’” writes Arianna Huffington of Huffington Post. “I like that brand. More importantly, voters — especially unlikely voters — like that brand. Pulling it off the shelf and replacing it with a political product geared to pleasing America’s vacillating swing voters would be a fatal blunder.”

A more useful way to assess Obama’s politics is to take a closer look at some of the dominant forces in the Democratic Party that he has openly embraced. While it is impossible to convey all the thousands of interlocking relationships that bind the corporate center of the Democratic Party, even a small sampling strongly suggests that it will take a lot more than voting for one man for us to see real change in this country.

Corporate money flows through many channels to reach congressional Democrats.

Candidates raise millions from lobbyists and corporations to fill their own war chests. Prominent Congresspersons also bring in hundreds of thousands of dollars for their personal political action committees, which they use to bankroll needy colleagues in return for future favors and support. And then there’s the Democratic Senatorial Campaign Committee (DSCC) and the Democratic Congressional Campaign Committee (DCCC), which raise and spend tens of millions of dollars to help Democratic candidates. The recipients of this largesse, of course, come into office indebted to the party’s congressional leadership.

Rep. Nancy Pelosi (Calif.) — Pelosi’s rise to the House Speaker’s chair was fueled by her fundraising prowess. Her largest contributor this election cycle is the powerhouse corporate law firm Akin & Gump.

Rep. Steny Hoyer (Md.) — House Majority Leader. Top donors include JPMorgan Chase and Comcast. His Political Action Committee (PAC) has received $15,000 in donations from top execs at MacAndrews and Forbes, whose chairman, Ronald Perelman, made hundreds of millions of dollars off the 1980s-era Savings & Loan crisis.

Rep. Rahm Emanuel (Ill.) — Widely credited with helping the Dems regain the House of Representatives in 2006 as the head of the DCCC, this former Clinton aide-turned-investment banker-turned Congressional leader is known for his relentless fundraising. Top donors to his own campaign include UBS AG, Blackstone Group and JPMorgan Chase. Emanuel’s PAC has also scooped up more than $600,000 in the 2008 election cycle, mainly from the finance, real estate and entertainment industries.

Sen. Chuck Schumer (NY) — Chair of the DSCC and a powerful member of the Senate Finance Committee, Schumer is a champion fundraiser with close ties to Wall Street who led the Democratic takeover of the Senate in 2006.

Rep. Charles Rangel (NY) — Chair of the House Ways and Means Committee, which writes tax legislation, Rangel has received over $4.1 million in campaign donations since he became the committee’s new chair in Jan. 2007. Meanwhile, his political action committee has been showered with $1.04 million in contributions, much of it from New York City real estate interests.

Rep. John Dingell (Mich.)