In fact, to me, the greatest thing about the bull market of the 1990s was how little Washington mattered at all. For all of the griping about the havoc that Democrats wreak on business, it was simply a benign time with a White House that was deeply wired to creating jobs and allowing the private sector to blossom.
In short, my conclusion about that era is that the genesis and sustenance of the bull market came from corporate profits. Tax rates just weren't much of a factor in decision making, certainly not as much as the certainty of knowing what they were and what they would be, with a Treasury Secretary from Goldman Sachs, Bob Rubin, who was in his prime and knew how to stay out of the way and get involved only when a foreign crisis, such as the Mexican bond debacle, intervened.
So enough with the Washington obsession. It was about corporations spewing cash as the world's economies expanded at a terrific pace. If you get that to happen again, the Clinton era bull market will be repeated.