Kathryn, you raise some good questions. Buck, it seems, does not like to be tagged as The Tea-Party Candidate. His answer reminded me of this:

UPDATE: A reader recalls what Buck said to NRO in June:

Yet when I call him a “tea-party darling,” Buck balks. “I am a grassroots guy,” he says. “The tea-party people appreciate my message because, like me, they are fed up with Republicans and Democrats. But the tea party is just one reason, not the reason, my campaign is doing well. Conversing with conservatives in all 64 counties of this state is the reason for that. We’ve built a solid base.”