Actually, this New York Times piece is a little more optimistic about the chances of many tea party candidates than I would have expected. Still, their number of tea party backed candidates who are ahead at this point - 33 is slightly below other estimates I've seen:
Of 129 Tea Party candidates for the House, 7 are running in solidly Republican districts - all but one of those seats is now held by a Republican. Another 7 are running for seats currently held by Democrats but in districts leaning toward the Tea Party Republican.
Nineteen are in tossup races, for seats that are held, with the exception of two, by Democrats. And 29 are running for seats in districts that are leaning Democratic - of those, only one is currently held by a Republican. Sixty-seven are challenging Democrats who are expected to win - though this is a year when the unexpected has been more rule than exception.
In the Senate, there are 9 Tea Party candidates running for a potential of 27 seats - not including those where the incumbent is the Republican nominee.
For purposes of the list, Tea Party candidates were those who had entered politics through the movement or who are receiving significant support from local Tea Party groups and who share the ideology of the movement. Many have been endorsed by groups like FreedomWorks or the Tea Party Express, or by conservative kingmakers like Sarah Palin and Senator Jim DeMint of South Carolina, but those endorsements alone were not enough to qualify as a Tea Party candidate.
As I said, a pretty fair assessment. There are some races that the Times may be writing off already but where the Tea Party candidate is surging, or where polls are non-existent or unreliable. I suspect there will be some surprises for the Times on election day.