Media coverage and commentary have vastly overstated the likely impact on federal election campaigns of the Supreme Court's Citizens United decision, which ruled that corporations have the same right to free speech as individuals. It has also obscured the extent to which members of Congress from both parties had previously opened the door for corporate and union financing in federal campaigns.

As associate director for policy of the Campaign Finance Institute from 2002-09, I wrote a number of studies showing the rise of corporate and union spending, via tax-exempt organizations, in federal elections. My research found that this spending supported media ads and grass-roots mail, phone and other communications that tore down or boosted candidates without using explicit phrases such as "vote for" or "vote against."

Full disclosure of the sources of financing was legally required only for "527" political organizations, which were mostly pro-Democratic and frequently union-backed. In contrast, no one knew for sure who was providing how much to largely pro-Republican "501(c)" trade associations and advocacy groups, such as the U.S. Chamber of Commerce and Freedom's Watch.

A provision in the 2002 McCain-Feingold campaign finance law did prohibit the use of corporate and union funds in one important area: TV and radio ads mentioning candidates 60 days before an election and 30 days before a primary. But this section of the law was basically gutted by the high court's 2007 decision in the Wisconsin Right to Life case, and especially by the subsequent implementing regulations adopted by the Senate-appointed Federal Election Commission.

Thus, during the 2008 Minnesota Senate race between Norm Coleman and Al Franken, the U.S. Chamber of Commerce was legally able to run an ad showing Democratic candidate Franken with duct tape over his mouth and this narration: "High taxes hurt. But it seems like every time Al Franken opens his mouth, he talks about raising taxes. This from a guy who was caught not paying his own taxes in 17 states. ... Maybe he shouldn't open his mouth. ... Tell Al Franken that high taxes aren't very funny (Franken's phone number flashes by)."

With last week's ruling, the justices granted corporations (and implicitly unions) a constitutional license to explicitly urge voters to support or oppose candidates in all communications, while interring the remains of the McCain-Feingold restrictions on ads.

Yet this decision is unlikely to change the political situation on the ground very much. Even before the Citizens United decision, business, labor and wealthy individuals (frequently major owners of corporations, such as Sheldon Adelson of the Las Vegas Sands or George Soros of Soros Fund Management) were already able to spend more than $400 million in the 2008 federal elections on communications with content similar to the Franken ad.

Some election lawyers who work for candidates and parties have expressed fear that candidates will now "lose control" of their campaign messages to well-financed outside groups. But while there have been a few such cases, they are relatively rare. Candidates and groups draw from the same well of polling and the same web of political consultants. They all have an interest in opportunistically emphasizing whatever it takes to win.

Finally, it is curious to see some of the same Democratic members of Congress who fought — on behalf of labor union allies — legislative proposals to rein in corporate and union-financed 527 political organizations now denouncing the Citizens United decision, which essentially ratifies a status quo they worked to protect.

It is also revealing that we heard little from members of either party when the Federal Election Commission emasculated the McCain-Feingold 60/30-day ad restrictions. Nor was there congressional resistance when the bipartisan FEC adopted a weak public disclosure regulation for such ads, one that does not require their 501(c) nonprofit corporate sponsors, such as the U.S. Chamber of Commerce or Health Care for America Now, to reveal their ultimate for-profit corporate, union and individual donors. Although the court last week upheld disclosure, this regulation still enables Citizens United to hide its donors.

If members of Congress are now serious about searching for new ways to limit the impact of corporate and union spending in elections and improving its disclosure, they should start by re-examining their own behavior.