Sarah Palin appears on Sean Hannity’s show to endorse Christine O’Donnell.

Four and a half days before Election Day? I suspect the O’Donnell folks would have preferred this a bit earlier, to give them more time to get this out there.

UPDATE: Guy Benson asks, “Were any hardcore Delaware Palinites planning to vote for Mike Castle next Tuesday? Just asking.”

This, I suspect, will help O’Donnell persuade grassroots conservatives that she’s not a nut. This is the Mama Grizzly seal of approval, and while the impact of Palin’s endorsement varies from state to state and race to race, Palin could easily have remained silent in this race. We will know within a few days whether this is the high point of the O’Donnell campaign, but there’s no disputing this is a high point.