It doesn’t matter if Louisiana is one of 18 states, recalls are only for state elections and state officials.
SCOTUS ruled that members of House of Representatives and Senators are federal employees, and as such cannot be recalled by states electorate once elected and seated.
So all these recalls of Senators are exercises in futility.
Maybe, but it is also very educational and lets Ms. Landrieu know that many are VERY unhappy with her.
Certainly giving preferences to states to in effect buy the senator's vote IS unconstitutional according to Article 1, Section 8:
The Congress shall have Power To lay and collect Taxes, Duties, Imposts and Excises, to pay the Debts and provide for the common Defence and general Welfare of the United States; but all Duties, Imposts and Excises shall be uniform throughout the United States;