At least from my view the Tea Party is mainly disaffected/disinterested Republicans plus some of what were once called Reagan Democrats/Perot voters.
They're socially conservative, but not actively so like the religious right.
They're fiscally conservative for others, but not for what they're "promised." (Because they "earned" that.)
They're overly patriotic, potentially nationalist. Populist in conceptualization.
They have a "semblance" of politics, but don't pay real attention to it really beyond "X is screwing up America!" And this is more of an animating force than the real specifics of either the social or fiscal issues. (And I think part of why they created the rise and fall from Bachmann to Perry to Cain to Gingrich to Santorum.)
I don't think direct overt racism actually is a significant force but notions of the "other" and a favorable opinion of "Christian white male" culture as "American" do make it...easier for the acceptance of "X" being the one screwing things up. Like Japan in the 80s, or Mexicans "stealing" jobs and education.
In other words, Hank and Peggy Hill. Hank has the "gut-feeling ideology" but isn't all that down with the protesting and such, while Peggy thinks the protesting is we're just being so wild and crazy! (And Bill is there because Peggy is.)
It's interesting to me how age has become a dividing factor in Obama/Tea Party era politics. Obama's split between the oldest and youngest voters was 16 percentage points, against about 8 percentage points for Kerry/Gore, and Clinton actually performed strongest among elderly voters (who, way back when, strongly identified as New Deal Dems). Part of that is obviously that the younger generations of Americans are swarthier, so once you factor out race it's not quite as striking. But it's still pretty significant, and relatively new.
Been thinking about it because the GOP, including the Tea Party faction, has acted very protective of SS and Medicare benefits for current or soon-to-be retirees, even while proposing major changes to the programs. Bush's push for SS privatization, Ryan's voucher plan for Medicare, the Romney campaign platform on Medicare all involved scaling back government guarantees, but all of them would spare older and middle-aged voters. Part of that is just political expediency (like Obama needing to be able to say "you can keep your insurance" when crafting the ACA), but it really is pitting people against each other by generation.
To a degree, the GOP has become the representative of the class interests of old folks, like those Pensioners Parties you see crop up in multiparty democracy (to really bring the conversation into a circle), and which had a dozen or so seats in the Knesset, IIRC. It might just be random opportunism making it seem that way, but it certainly makes the GOP/Tea Party positions, such as they are, a bit more internally consistent.
Also, Hank is not spiteful or panicky enough to be in the Tea Party, and Peggy would not let herself admit to being frightened of anything new and popular with young folk. The Tea Party is the party of Cotton Hill.