In the context of the Democratic party, “centrist” can have two very different meanings: the center of the party, and “centrist” in a traditional, global, left-right sense. You are right that the reforms I suggest would tend to favor the center of the party — but insofar as most voters really do want change (and I think that’s mostly true), that is a very different thing from the traditional “centrist”. In fact, I believe that the reforms I support most would be more likely to elect a “change agent”, while the inferior methods would be more likely to elect a “bland, status-quo candidate” — because the latter, not the former, is on the fringe of the party as it currently stands.