Joll, think middle-class baby boomers with a Prudy Pingleton-like reaction to black people and immigrants. They believe government is "out of control", without a clear definition of whether that means too large, too spendthrift or just enacts policies they don't agree with or understand.
The irony is this group was nowhere to be found during the Bush/Cheney or Reagan years, when the US seemed determined to spend itself down to the molten core of Earth itself.
Rabble-rousers and underwriters of the Tea Party are largely invisible to the majority of the movement, and include the Koch brothers of Texas and other extremely wealthy people who essentially want to pay no taxes and do whatever they want to with government land and resources (pollute, develop, drill, stripmine, etc.). It's not that Obama is any less fiscally wise than Bush was; just that he's threatening to let the Bush tax cuts expire.
Given that Reagan and Bush II reliably slashed taxes on the unimaginably wealthy, hurtling the country every deeper into deficit spending, there was no reason for the ultrarich to underwrite or foment a revolt.
Despite scant evidence that deeply cutting the taxes of the very rich results in more jobs or any sort of economic growth, it remains a cherished refrain of the Republican party. Tea Party members seem sort of confused by all this, since most of them personally will see their taxes go down under Obama. Still, they seem to be scared out of their skulls by something vague -- they tremble and even cry real tears that our government has become "socialist", arrogant and unpredictable. Oh, and they don't like people of color, gays, immigrants or Muslims.