Take a look at the difference between the Clinton years and both the Reagan and George W. Bush years when it comes to economic performance. Under Clinton's policies, not only did every single income group do better than they did under either Reagan's or Bush's policies, the growth was more even.
The growth gap between the bottom quintile and the top 5% is particularly striking. Under Clinton, the bottom quintile grew almost as much as the top 5%. Under Reagan, it grew by barely more than a third as much. And under Bush, incomes dropped by eight times more for the bottom quintile than the top 5% on a percentage basis.
The thing that unites both Reagan and Bush, aside from their party? They were both supply-siders who cut taxes, especially on the top earners.
Clinton believed the demand side of the equation is important too, and he raised taxes, particularly on top earners. Some people like to call that class warfare, but guess who benefited? Everybody. Including the wealthiest Americans.
Political strategists and pollsters will often try to argue that it's a political death sentence for a Democrat to raise taxes. But as Clinton's experience shows, it would be a mistake for Democrats to overlearn the lessons of Walter Mondale's 1984 campaign. Sure, Bill Clinton raised taxes, but the thing we remember about his economic policies wasn't that taxes went up -- it's that his policies worked, the economy boomed, everybody made more money, the country was on stronger fiscal footing, and the government was operating more effectively. That doesn't mean Democrats should campaign on a tax hike. But it does mean we shouldn't be afraid of returning to Clinton era fiscal policy. It worked then, and it can work again.