So just to stoke the flames of 2008 speculation, here's a list of potential candidates; who would you like to see?
Sen. George Allen (R-VA)
Sen. Sam Brownback (R-KS)
Sen. Bill Frist (R-TN)
Sen. John McCain (R-AZ)
Gov. George Pataki (R-NY)
Gov. Mitt Romney (R-MA)
Sen. Rick Santorum (R-PA)

vs.

Sen. Evan Bayh (D-IN)
Sen. Joe Biden (D-DE)
Former Sen. John Edwards (D-NC)
Sen. Hillary Clinton (D-NY)
Gov. Tom Vilsack (D-IA)
Gov. Mark Warner (D-VA)

Personally, I like anyone who keeps appearing on The Daily Show with Jon Stewart. Joe Biden against "Man on Dog" Santorum? Rock on! What's your call?