Yesterday, Think Progress dropped a campaign finance bombshell when it reported that the US Chamber of Commerce, which is spending tens of millions of dollars this year to run ads supporting GOP candidates in federal elections, is collecting hundreds of thousands of dollars from foreign owned businesses, including companies owned by foreign governments.

Reliable clean elections proponents, like Minnesota senator Al Franken, spoke out immediately for the FEC to investigate the Chamber’s finances. But the voices in support of campaign finance disclosure haven’t been coming only from the left.

CNBC host Larry Kudlow, a columnist for the conservative National Review, said today that groups like the Chamber and Karl Rove’s shadowy group Crossroads GPS should put their funding and spending records out in the open. According to fact sheet from House Speaker Nancy Pelosi’s office, Kudlow said:

“Why not have the media posting of the contribution information on the Internet? That’s all. And let everybody decide… Who, what, when, how, where, who got it? Put it up on the net and let free speech and free politics take its work… American Crossroads and Karl Rove and all them should post also.” [10/6/10]

We reported last week on several groups, including the Chamber of Commerce and Crossroads GPS, that are spending buckets of money to back pro-corporate candidates in this year’s elections, while under no obligation to disclose where their money is coming from. This spending is no small change—the Associated Press reported last week that right-wing, pro-corporate groups have outspent progressive groups 6-1 on television ads this year.

Kudlow’s call for disclosure from these big-spending groups should come as no surprise. Disclosure of campaign spending is a principle embraced by many prominent conservatives, including Justice Antonin Scalia. And when the Supreme Court’s conservative majority ruled in Citizens United v. FEC to allow corporations to spend unlimited amounts of money to influence elections, they did so with an important side note: they were in favor of “prompt disclosure” of the campaign spending.

Up against the reality of corporate-backed groups that will spend enormous amounts of money for their electoral benefit, however, congressional Republicans have been significantly less eager to embrace the idea of full disclosure than that of free spending.

The Chamber of Commerce, for one, seems to be solidly in the congressional Republican camp on the disclosure issue. Asked by the Washington Post’s Greg Sargent about Think Progress’s allegations, a spokeswoman for the Chamber responded with a tirade against the blog, denying that the Chamber spends foreign money on electioneering—but refusing to answer any questions on just how that money is kept separate.