In: Sen. Tom Harkin (D-IA), Gov. John Kitzhaber (D-OR), Gov. Phil Bredesen (D-TN), Gov. Kathleen Sebelius (D-KS). Out: John Podesta, Mitt Romney. Bredesen, I am told by a good source, is a serious prospect; not sure about Harkin or Kitzhaber. A key Democrat who works with the White House on health care is worried about Bredesen, e-mailing me last night that he "does not share the President's principles" on health care. Here's some background on that.