I don't think that Clinton really proved that tax cuts don't matter. His economy was fueled by record low oil prices. When you've got $14 a barrel oil, you can absorb a lot of other bad news.
Not to mention defense cutbacks. I guess the bottom line is that outside very broad macro components, such as a functioning legal system that protects private property, capitalism is left up to the market. Since innovative people don't like sitting around, they are left to creating new gadgets, entertainments, etc. Demand by others creates money supply growth, and viola, we're off to the races...