Grover Norquist’s iron grip over much of the Republican Party is somewhat puzzling. Why should Senators and other lawmakers listen to a guy caught laundering money for Jack Abramoff?

But consider Norquist’s tax pledge and political power another way: that he’s just a proxy for the powerful interest groups that finance him. In the nineties, it was big tobacco that used Norquist’s tax pledge as a cover to lobby lawmakers against cigarette taxes (Norquist still uses an e-mail system donated to him by Altria to send out Tea Party action alerts against tobacco taxes). Now, big PhRMA and other industry groups provide grants to Norquist while his foundation endorses other giveaways, like protectionist support against importing cheaper drugs from Canada and the classification of tax subsidies to refineries as “tax cuts” that must not be cut