Never underestimate Congress’s ability for racial mischief. In the Jim Crow era, Southerners blocked civil-rights progress. Now, 50 years after the Civil Rights Act of 1964, the liberal goal is to give national politicians more power to play racial politics in a few unfavored states.

Democrats and the strange bedfellow of Wisconsin Republican James Sensenbrenner have introduced a bill to revise Section 4(b) of the 1965 Voting Rights Act that the Supreme Court struck down last year. Chief Justice John Roberts wrote that the Act’s coverage formula no longer made sense in light of current racial realities, and the new proposal isn’t much better.

The old formula required nine states and parts of seven others to have all changes to their voting laws precleared by the Justice Department or a federal court. The new formula would reinstate preclearance for Texas, Louisiana, Mississippi and Georgia for what lawmakers claim is evidence of racial bias in voting laws.

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