The billionaire brothers David and Charles Koch no longer sit outside Washington’s political establishment, isolated by their uncompromising conservatism. Instead, they are now at the center of Republican power, a change most evident in the new makeup of the House Energy and Commerce Committee.

Wichita-based Koch Industries and its employees formed the largest single oil and gas donor to members of the panel, ahead of giants like Exxon Mobil, contributing $279,500 to 22 of the committee’s 31 Republicans, and $32,000 to five Democrats.

Nine of the 12 new Republicans on the panel signed a pledge distributed by a Koch-founded advocacy group – Americans for Prosperity – to oppose the Obama administration’s proposal to regulate greenhouse gases. Of the six GOP freshman lawmakers on the panel, five benefited from the group’s separate advertising and grass-roots activity during the 2010 campaign.

Claiming an electoral mandate, Republicans on the committee have launched an agenda of the sort long backed by the Koch brothers. A top early goal: restricting the reach of the Environmental Protection Agency, which oversees the Kochs’ core energy businesses.

The new committee members include a congressman who has hired a former Koch Industries lawyer as his chief of staff. Another, Rep. Morgan Griffith […]