I watched a forum with some guys (back in 2009 I think) that started to get into the Tea Party(TP). Their idea was more or less to prosecute bankers and who frauded and don't bail banks. I was under the impression that they were pretty libertarians (for legalization of drug for example). They joined the TP to have some avenue to protest and since some other TPers also opposed the banks bailout at the time, it didn't seem such a bad idea. The problem is that their voice got drowned out by social conservatives and now they pretty much left the movement and are disgusted by it.
I don't really have evidence but I think that what happened is that lots of people were unhappy with the banks, joined the TP and since a number of conservatives were also against bank bailouts (gov intervention), they also joined in. Some republicans took advantage of it and took the TP under their wing, now the protest against the financial system (that were the first reason many joined the TP in the first place) has been forgotten and replaced with the usual party lines.
Edited by Son, : No reason given.