It's like the floating definition of "The Rich"
It seems to be anyone who has more money than you, no matter how much that may be. It makes for good sound bites, such as when Hillary last week called for more taxes on "the Rich" without bothering to define where the cutoff point is. She and those who think like her also have a tendency to overlook the fact that the top 1% of wage earners pay 36.2% of all taxes and the top 10% pay 66.5% of all taxes (1999 figures).
BTW: anyone whose family income was over $87,682 in 1999 was in the top 10%. We're not exactly talking Beverly Hills income territory.