This 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):

-- How did Barack Obama's speech on race in America play? And how effective will conservative efforts to question his love of country actually prove? National Review's David Freddoso joins Politics Nation to discuss.

-- Democrats continue to haggle over revotes in Michigan and Florida, while the Supreme Court weighs in on who exactly owns the primary process. Both campaigns talk about the "will of the voters" in primaries, but do those claims actually ring true?

-- A prominent New York Republican announces his retirement, a move that sheds more light on a disappointing landscape for the national GOP. But could a primary challenger in Alaska actually improve the party's fortunes? CongressDaily's Erin McPike talks congressional politics.

-- And what should be made on the first few days of the NCAA tournament? Who's looking especially impressive? A special guest joins Reid Wilson and Josh Kraushaar to dissect what we've seen so far.

All that and more, tomorrow morning on Politics Nation, only on XM Radio's POTUS '08. Listen live, tomorrow at 10 a.m. to noon.