I always thought that class was determined, roughly, by income quintiles. Apparently I’m wrong.
Eliminating the Social Security tax cap without changing the benefit formula could undermine support for the program among the roughly five percent of Americans who earn more than $97,000 per year.
[…]While Obama has suggested imposing the 12.4 percent [social security] tax on all income above $97,000 per year, Edwards would only impose it on those making more than $200,000 per year. Income between $97,000 and $200,000 would continue to be exempt from Social Security taxes under the Edwards proposal.
“I do think we need to have a bubble above $97,000, probably up to about $200,000 so we don’t raise taxes on middle-class families,” Edwards said at Thursday’s AARP forum. “But, above the $200,000, these millionaires on Wall Street ought to be paying their Social Security taxes.”
It simply does not make sense to me how someone in the top 2-3% of income earners can be considered “middle class.”

It’s because no one in DC can live decently for under $97K so that is the breakpoint to being middle class. Above $200K though you are getting after it there, so it’s Democrat tax time. Gotta support those self imposed pay hikes congress gives itself (not that the elephants are tremendously better about this).