At PJ Media, J. Christian Adams points out that the Republican National Committee recently and congressional Republicans back in 2006 backed Section 4 of the Voting Rights Act, which was declared unconstitutional last month by the Supreme Court in a tartly written decision by Chief Justice John Roberts. Section 4 required certain states, determined by the degree of voter participation in elections between 1964 and 1972, to get approval — ”preclearance” — of any changes in election law by the Justice Department or a D.C. federal court.

The reason Republicans backed these measures is no secret: The prevailing interpretation of the Voting Rights Act requires maximizing the number of majority-minority (i.e., majority-black or -Hispanic) congressional and legislative districts. That leaves adjacent districts with relatively low numbers of heavily Democratic blacks and Hispanics and therefore more likely to elect Republicans. I remember that in the 1990 redistricting cycle, Florida Republicans allied with black Democrats to support a congressional redistricting plan which produced three black-majority districts and gave Republicans a better chance to win most of the others. This at a time when Democrats controlled the governorship and both houses of the state legislature. Such plans have become even more common as Republicans have come to control more legislatures, especially in the South, in the 2000 and 2010 redistricting cycles.

It seems likely, and Adams’s blogpost suggests, that Republicans no longer will support requiring preclearance in the mostly Southern states which were covered by the 1964-72 criteria in Section 4. Democrats are calling for a new Section 4, which Chief Justice Roberts said would be valid if based on more recent criteria. But what criteria could they use? Black voter participation was apparently higher than white voter participation in 2012. Using low voter participation as a criterion might require California (where Hispanics vote in very low numbers and where neither party makes much effort to increase turnout) to get preclearance of changes in election law. The California delegation is unlikely to support that.

Attorney General Holder’s (I think misguided) threat to sue Texas under Section 3, which bans voting discrimination, shows that the Voting Rights Act have provisions to target genuine racial discrimination even in the absence of Section 4. But there doesn’t seem to be much of it. And some of it — the discrimnation by black officeholders against whites in Noxubee County, Mississippi — is not something the Holder Justice Department has shown any desire to target, as J. Christian Adams, who used to serve in its voting rights division, has written.