The Washington Post reports: The political network spearheaded by conservative billionaires Charles and David Koch has expanded into a far-reaching operation of unrivaled complexity, built around a maze of groups that cloaks its donors, according to an analysis of new tax returns and other documents.

The filings show that the network of politically active nonprofit groups backed by the Kochs and fellow donors in the 2012 elections financially outpaced other independent groups on the right and, on its own, matched the long-established national coalition of labor unions that serves as one of the biggest sources of support for Democrats.

The resources and the breadth of the organization make it singular in American politics: an operation conducted outside the campaign finance system, employing an array of groups aimed at stopping what its financiers view as government overreach. Members of the coalition target different constituencies but together have mounted attacks on the new health-care law, federal spending and environmental regulations.

Key players in the Koch-backed network have already begun engaging in the 2014 midterm elections, hiring new staff members to expand operations and strafing House and Senate Democrats with hard-hitting ads over their support for the Affordable Care Act.

Its funders remain largely unknown; the coalition was carefully constructed with extensive legal barriers to shield its donors. [Continue reading…]