Former Alaska Gov. Sarah Palin (R) endorsed Indiana state Treasurer Richard Mourdock (R) over Sen. Dick Lugar (R-Ind.) in their primary contest, she announced Friday afternoon.

"Indiana deserves a conservative in the Senate who will fight for the Hoosier State, uphold our Constitution, and not just go along to get along with the vested interests of the permanent political class in D.C.," Palin wrote on Facebook in her endorsement. "Richard Mourdock is the conservative choice for Indiana. Senator Lugar’s 36 years of service as a Senator are appreciated, but it’s time for the torch to pass to conservative leadership in Washington that promises to rein in government spending now."

Palin becomes the latest Tea Party standard-bearer to endorse Mourdock: Herman Cain, radio host Mark Levin and RedState's Erick Erickson also support him, as do the Tea Party-affiliated groups FreedomWorks and the Club for Growth, both of whom have spent heavily to help him win. Other conservative groups backing Mourdock include the National Rifle Association, the Family Research Council and the American Conservative Union.

Lugar has the support of Indiana Gov. Mitch Daniels (R) as well as the pro-business U.S. Chamber of Commerce. The two are neck-and-neck in their contest, according to recent polls, with the primary rapidly approaching on May 8.