Palin phoned in to Hannity's radio show today with the endorsement, an "exclusive," according to the conservative host.
It's a big question as to whether Palin's endorsement's carry much weight. Her batting average isn't great, but she's helped pluck lesser-known candidates from obscurity this year. As we reported, O'Donnell recently met with Palin and asked for her endorsement.
Check out our coverage of the race here.
Late Update: Palin explains further on her Facebook page:
The wave of positive change can really sweep across our land with the election of Constitutional Conservatives who promise to use common sense and rein in the federal government spending! Please support Christine O'Donnell in Delaware. She will support efforts for America's energy security, patient-centered health care reform, cutting government waste, and letting the private sector thrive and prosper! We can't afford "more of the same" in Washington. Christine will help usher in the real change we need to get America on the right track. Please visit her website at www.christine2010.com and follow her on Facebook and Twitter.