The piece includes quotes from Rep. Sensenbrenner, and also this tidbit:

Many of the states and donors who have supported discriminatory voting laws are also backing Blum. His Project on Fair Representation is exclusively funded by Donors Trust, a consortium of conservative funders that might be the most influential organization you’ve never heard of. Donors Trust doled out $22 million to a Who’s Who of influential conservative groups in 2010, including the American Legislative Exchange Council (ALEC), which drafted mock voter ID laws and a raft of controversial state-based legislation; the Americans for Prosperity Foundation, the Koch brothers’ main public policy arm; as well as Grover Norquist’s Americans for Tax Reform Foundation. Donors Trust has received seven-figure donations from virtually every top conservative donor, including $5.2 million since 2005 from Charles Koch’s Knowledge and Progress Fund. (The structure of Donors Trust allows wealthy conservative donors like Koch to disguise much of their giving.)

From 2006 to 2011, Blum received $1.2 million from Donors Trust, which allowed him to retain the services of Wiley Rein, the firm that unsuccessfully defended Ohio’s and Florida’s attempts to restrict early voting in federal court last year. As a “special program fund” of the tax-exempt Donors Trust, Blum’s group does not have to disclose which funders of Donors Trust are giving him money, but he has identified two of them: the Bradley Foundation and the Searle Freedom Trust. The Wisconsin-based Bradley Foundation paid for billboards in minority communities in Milwaukee during the 2010 election with the ominous message “Voter Fraud Is a Felony!”, which voting rights groups denounced as voter suppression. Both Bradley and Searle have given six-figure donations to ALEC in recent years, and Bradley funded a think tank in Wisconsin, the MacIver Institute, that hyped discredited claims of voter fraud to justify the state’s voter ID law, currently blocked in state court.