Reagan and Clinton both presided over massive deregulation efforts across wide ranges of industry, and there is very obvious correlation between those efforts and the economic changes in the last 30 years. The widening of the gap between rich and poor maps very closely with tax reduction policies that disproportionately help the wealthiest and industry deregulation, particularly of the finance industry. The housing crisis of 2008 would not have happened under the regulatory regime of 1988.

And no, correlation is not causation. (The housing crisis of 2008 was not caused by deregulation, and there's a lot of blame to be shared across the political spectrum.) But it's hard not to notice over the long term that when the crazy leftists predict X will happen after a given massive act of deregulation and the sane rational libertarians predict Y, for the last thirty years we've almost always gotten X. And the libertarian response is always, "It's because you just didn't deregulate enough." Well, yes, that's one possible conclusion...