Two-term Tennessee Sen. Lamar Alexander has pulled off a surprise for Washington-based Tea Party groups eagerly looking for a more conservative alternative to make a primary challenge in 2014: He's already the movement's cup of tea.

A new poll from Vanderbilt University's Center for the Study of Democratic Institutions found that 62 percent of Tennessee voters who describe themselves as Tea Party activists approve of Alexander, a one-time presidential candidate and education secretary under former President George H.W. Bush.

That's even higher than Republicans in the state. They give Alexander a 60 percent approval rating, followed by 54 percent among Democrats and 53 percent for independents.

The Tea Party support is expected to slow efforts to find an conservative to challenge Alexander in the primary. "With near universal name recognition in Tennessee and approval numbers this high, any political special interest group in Washington thinking about targeting Lamar would be throwing away money. These numbers are the equivalent of a 'challenger beware' sign," said one GOP strategist.

FreedomWorks, a major Tea Party organizer, has been in the state but no challenger has emerged. "We are in the process of talking and getting feedback from the activists on the ground, but we're watching the race closely," said spokeswoman Jacqueline Bodnar. "I can tell you anecdotally that there are lots of activists open to supporting a principled challenger if one comes along."

In addition to the surprising Vanderbilt poll, Alexander is receiving support from Tea Party favorite Mike Huckabee, the former Arkansas governor, 2008 presidential candidate and current Fox News host. He is joining Alexander in late July for a state GOP event. They plan to play some music and having invited a special country music guest to join them, said an aide.