Eliza Newlin Carney behind the CQ paywall (but soon to be free! yay!):

In theory, a recent report that finds American companies are taking steps to shed more light on their political spending should score a conservative home run.

That’s because the stepped-up disclosures described in the report, released last month by the watchdog group the Center for Political Accountability, are entirely voluntary. Conservatives typically champion self-regulation as preferable to government regulation. And the Fortune 500 companies ramping up their disclosures — from Prudential to JP Morgan Chase, Exelon and General Mills — are mainstream corporate leaders often allied with the GOP.

But last month’s report, released in tandem with the Zicklin Center for Business Ethics at the University of Pennsylvania’s Wharton School, drew instant fire from the Center for Competitive Politics, which promotes political deregulation. The CPA-Zicklin Index “is a deceptive tool used to sell more and more companies on the idea of corporate ‘transparency’ with the partisan goal of removing these voices from the public policy debate altogether,” declared a center blog post.

Bradley Smith, who heads the center and chaired the Federal Election Commission in the George W. Bush administration, says the report falsely asserts that corporate political activity poses reputational and ethical risks. He assails what he calls the report’s “illiberal purposes of attempting to silence political speech through intimidation and harassment.”

But corporate executives say political disclosure is simply good business practice. Some are responding to shareholders who have petitioned to draw back the curtain on political activities. Others describe political transparency as part of a broader culture of corporate accountability that helps their companies’ bottom lines.