ANCHORAGE, Alaska -- There are two things people here remember about Sarah Palin's debating style during her race for governor two years ago.

One is the stack of color-coded cue cards she took to the podium for help whenever she was asked a policy question. The other is how quickly she was able to shuck those props, master the thrust-and-parry of jousting with her opponents and inquisitors, and project confidence to an audience of television viewers watching from home.

"That's the Sarah Palin I remember from the 2006 debates: positive, confident and upbeat," recalls Libby Casey, an Alaska public-radio reporter who served as a debate moderator on two occasions that year.

That's a contrast from the image projected by Gov. Palin in recent TV interviews in which she has seemed shaky on basic facts -- performances that have made even many of her fellow Republicans nervous about the vice-presidential debate scheduled for Thursday. Her Democratic opponent, Sen. Joe Biden of Delaware, is a veteran of three decades of congressional deliberations, as well as two rounds of presidential-nominating contests with their own sets of debates. And it may take more than style points to reassure viewers rattled by relentless news this week of economic dislocation.