It’s called a party though it’s not a party, though even that depends whom you ask. It’s not in the business of endorsing candidates except when it is, and has no interest in the establishment even though one member is running for governor. Welcome to New York’s Tea Party movement. What began in early 2009 as a series of protests against the Obama administration’s stimulus plan and health-care legislation has grown into a bona fide political force that has asserted itself into state and local politics. (There are over 100 groups in New York state alone, although membership ranges from...