Madison saw the Constitution as forming a “happy combination” of a republic and a democracy, with “the great and aggregate interests being referred to the national, the local and particular to the State legislatures” resulting in a decentralized governmental structure. In his view, this would make it “more difficult for unworthy candidates to practice the vicious arts by which elections are too often carried.”
This view is supportive of an R-60 initiative being initiated by action of State legislatures. The ‘particular’ interests of the Madison quote would be addressed primarily by the States.
In addition, ballot initiatives increase voter participation. Higher voter turnout is generally favorable to the function of our republic/democracy.