Saturday morning, from 10 a.m. to 12 noon Eastern, join Politics Nation on XM Radio's POTUS '08, when we'll tackle the week in politics. Listen free here (link about half-way down the page) as:

-- Newly elected Democrat Travis Childers won a special election this week that sent shockwaves through the GOP establishment. We talk with Democratic pollster John Anzalone, who helped Childers win, to find out if the victory can foreshadow big things in November.

-- Along with the Democratic presidential primary, Oregonians are going to choose a candidate to battle incumbent Republican Senator Gordon Smith in November. We'll talk with State House Speaker Jeff Merkley and Portland lawyer and activist Steve Novick, the two front-runners, about why they are best to beat Smith in November, even as public polls have showed both trailing.

All that and a few surprises, we're sure, Saturday morning on Politics Nation, only on XM Radio's POTUS '08. Listen live, Saturday from 10 a.m. to noon Eastern and again at 6:00 p.m. Eastern.