Three "reform" groups that played key roles in enacting the McCain-Feingold campaign finance law to curtail spending in federal elections now say that overall spending in next week's mid-term elections will shatter all previous records, Public Policy Matters finds.

The Center for Responsive Politics said Republicans are benefiting from the spending, Common Cause said spending in close races could reach $250 million by Tuesday's election, and Public Citizen said in a report that independent spending by outside groups is largely hidden from public disclosure.

Public Citizen adds that, of the $176.1 million spent by outside groups using large, often undisclosed contributions to influence the current elections, just 10 groups are responsible for the bulk of the spending.

And it says that 59.9% of the money comes from undisclosed sources. Of those contributions that have been disclosed, nearly two-thirds have come from just 0.12% of the contributors. Public Citizen says the analysis of the data is available at http://www.citizen.org/documents/2010-Independent-Electioneering-Activities.pdf

More detail:

•At least 149 independent groups have spent money to influence this year’s elections (according to Federal Election Commission reports through Oct. 25) in the wake of the U.S. Supreme Court’s decision in Citizens United v. Federal Election Commission, which permitted corporations, unions and organizations they fund to spend unlimited money to influence elections, Public Citizen says.

•Those groups have spent $176.1 million. Of that, $114.6 million, or 65%, was spent by only 10 groups, Public Citizen says.