Based on this 2010 mapping of Tea Party groups.
Remember, the Tea Party didn't exists prior to February 2009.
This excerpt from "What is the tea party? A primer" (Washington Post, 9/15/2010) is prescient while also raising a red flag.
In January, tea party activists helped Republican Scott Brown win a special election for the late Ted Kennedy's Senate seat in traditionally blue Massachusetts. Tea Party Express spent about $350,000 in Massachusetts to help Brown win. (He has since angered some tea party activists by supporting President Obama's financial reform.)
On February 4, 2010, 600 tea party activists gathered in Nashville for the first Tea Party Convention, organized by the Web site Tea Party Nation. Palin was the keynote speaker.
Republican leaders began trying to use the party to rally opposition to health-care legislation and generate support for Republicans in the 2010 midterm elections. Sen. Jim DeMint (R-S.C.) in particular has embraced the tea party. But some Republicans remain wary, worried that tea party candidates could prove hard to manage if they are elected. [Emphasis added]