Jennifer Rubin has a piece on Contentions blog that highlights what any rational, reasonably intelligent person could have figured out during the campaign; Obama was lying when he said he would raise taxes only on the rich:

President Obama's proposed changes to the tax code, combined with exploding entitlement costs, will lead to ever-growing debt, according to independent estimates. The big question for Obama and his economic team will be whether he can meet the rising costs with increased tax revenue only from small slices of the electorate.

[snip]

Many economists, including some who voted for Obama, do not believe that he can indefinitely avoid imposing tax increases much further down the income scale - on the middle class.

Yes, they can seek more revenue from the rich, but the top 1% are already paying about 40% of the tax bill and the top 20% are paying about 70%. You can try to keep raising corporate taxes, but we already have one of the highest rates in the world, well in excess of European countries. So the only group to tap is the middle class, especially since spending has taken off with no end in sight:

More revenue will be needed to service the growing national debt. Because annual deficits are expected to remain above $500 billion for the next decade, [former Reagan economic aide and Obama supporter Martin] Sullivan expects debt payments to more than double, from about 1.2 percent of GDP to more than 3 percent.