It depends on how rich you are. As this chart, from Timothy Noah's interesting series on inequality in America, shows, over the last 50-odd years, income growth rates have been more equitable and more favorable to the less well off under Democratic presidents.
The obvious rejoinder to this data is that the effects of one administration's policies bleed into the term of another so it's hard to separate who's responsible for what. But this is still a much clearer pattern than I expected to see. Certainly if we extend the Bush tax cuts, as Republicans want, that will be a big boon to the people at the top without really helping small businesses much.