The Supreme Court’s invalidation of Louisiana’s congressional map has triggered a swirling debate about just how fundamentally the justices altered the Voting Rights Act landscape.  Even the justices themselves disagree. The conservative majority brands it as merely an update. The liberal dissenters say it’s nothing short of demolishing the landmark 1965 law.  It has left states scrambling to make sense of it as they consider racing to redraw their maps in advance of this year’s midterm elections. The changes, explained  Section 2 of the Voting Rights Act has enabled groups to force states to draw additional majority-minority districts for decades.  The provision bars voting maps that give a racial minority “less opportunity than other members of the electorate” to elect their preferred candidate. Wednesday’s decision doesn’t strike down Section 2.…