three-judge courts

In Shapiro v. McManus the Supreme Court held unanimously that a three-judge court must be convened to decide a constitutional challenge to a redistricting plan even if the judge to which the request was made doesn’t think the challenger will win.  

Stephen Shapiro, dissatisfied with Maryland’s “crazy-quilt gerrymandering,” sued Maryland arguing its congressional redistricting plan violated his First Amendment right of political association. While a plurality of the Supreme Court stated in Vieth v. Jubelirer (2004) that political gerrymandering cases cannot be brought under the Equal Protection Clause, Justice Kennedy, concurring in the same case, suggested such claims may be possible under the First Amendment.