The TEA Party was a money making scam. The biggest winner was Glenn Beck with Sarah Palin taking a close second.
The tea party is a lot of things.
First, it's a media distortion. The Tea Party gets FAR more coverage than numbers call for.
The Progressive wing of Democrats is far larger but gets a small fraction of the coverage.
Second, it's a predictable offshoot of the Republican party, with some others - it's the catchall 'we're pissed over something, maybe big government' citizen.
Where do Republicans go after 'their side' gets power and might be the worst in history?
Thirdly, it's an attempt by fringe interests to build their base by catching this falloff. Opportunists, interests like the Koch brothers, try to weasel in and get voters.
Fourthly, it's a lost opportunity for the backlash against bad government being more productive, when we really can use protest against a lot of the abuses.
For example, part of the Tea Party is anti-corporatist, even while the corporatist agenda seems to do better (e.g., polluters wanting to gut the EPA).
As so often in politics, it's a naive faction likely to cause harm and the opposite of what many of its members want. The spending they'll cut is the spending good for the public.
Its catchall role can't last - eventually the mutually exclusive interests in the party will battle, and 'just pissed off' won't be the dominant message if it's going to do anything.
The low-hanging fruit is 'change' on some things - throw a monkey wrench in the works, oppose earmarks, oppose a lot of traditional spending - and they're already falling apart over that as Republicans who wanted the benefit of the affiliation don't want some of the costs.
A main danger they pose is diluting the reform movement, and/or having their agenda co-opted by opportunist interests, with demagogues for leaders.
Unfortunately, it's a recipe for cynicism as its members lose faith in the American system - though some of that might be useful when the system is so corporatized.
It'd be nice if they split Republican votes enough to help elect Democrats.