Here’s what Biden said earlier this month:

“I hope one of my roles as vice president will be as the person actually implementing Barack Obama’s policy. You gotta get the Congress to go along with it,” he said. “And it’s presumptuous to say, but I know it pretty well. And I think I am fairly respected on both sides of the aisle.”

And here’s Palin making basically the same point after being asked by a third-grader what the Vice President does. The crux of the complaint is her shorthand that the VP’s “in charge” of the Senate to explain that the VP is, technically, president of the Senate, even though he/she doesn’t actually preside, and has the power to cast tie-breaking votes. Presumably the hoped-for answer was, “Engage in behind-the-scenes lobbying with Senators to advance the president’s agenda,” while making balloon animals. Or maybe, “Nothing, it’s a largely ornamental position,” followed by a game of Got Yer Nose.