Democrats who are running:* New York Sen. Hillary Rodham Clinton * Connecticut Sen. Chris Dodd * Former North Carolina Sen. John Edwards * Former Alaska Sen. Mike Gravel * Ohio Rep. Dennis Kucinich * Illinois Sen. Barack Obama * Gov. Bill Richardson of New Mexico * Former Iowa Gov. Tom Vilsack * Delaware Sen. Joe Biden (has said he is running, but has not yet filed paperwork with the Federal Election Commission)Potential Democratic candidates:* Retired Gen. Wesley Clark * Former Vice President Al GoreRepublicans who are running:* Kansas Sen. Sam Brownback * Former Virginia Gov. Jim Gilmore * Former New York City Mayor Rudy Giuliani * California Rep. Duncan Hunter * Arizona Sen. John McCain * Texas Rep. Ron Paul * Former Massachusetts Gov. Mitt Romney * Colorado Rep. Tom Tancredo * Former Wisconsin Gov. Tommy ThompsonPotential Republican candidates:* New York Mayor Mike Bloomberg (also a potential independent candidate) * Former House Speaker Newt Gingrich * Nebraska Sen. Chuck Hagel * Former Arkansas Gov. Mike Huckabee * Former New York Gov. George Pataki