Yes, it is a milestone that registered Democrats in Louisiana no longer comprise a majority of registered voters, and that blacks now comprise a plurality of registered Democrats. But, from published comments about these phenomena (predicted in this space months ago), there appears to be little accurate understanding about why this has happened.
One of my colleagues, and reported also “several political observers,” asserted that the presence of the blanket primary (incorrectly termed an “open” primary in the report) what was helped bring about this state of affairs. In fact, more than anything the ability for voters in a first election to cast ballot for candidate where all run together in all state and local and most federal contests form almost four decades has blunted the conversion of Democrats because the system does not penalize voters registered as Democrats from having influence with Republican partisan decisions.
The most important decision a party can make, and the greatest place where registrants can influence a party’s fortunes, is in selection of a party’s nominees to offices.