Main article: 2008 Presidential Candidates

Politicians with ambition have begun to express formally their desire for the presidency in the form of "exploratory committees," which allow the hopeful to raise money and travel without having to follow certain financial restrictions mandated by federal law. With official events, such as debates and candidate forums, beginning as early as February 2007, the status of a candidate will be based on whether or not he or she is invited. Several minor candidates in the past have tried to litigate their way in, generating some publicity but little public support.

Main article: 2008 Democratic presidential candidates

Main article: 2008 Republican presidential candidates

• Joe Biden, U.S. Senator from Delaware (Campaign Site)
• Hillary Clinton, U.S. Senator from New York and Former First Lady (Campaign Site)
• Christopher Dodd, U.S. Senator from Connecticut (Campaign Site)
• John Edwards, Former U.S. Senator from North Carolina and 2004 Democratic Vice Presidential candidate (Campaign Site)
• Mike Gravel, Former U.S. Senator from Alaska (Campaign Site)
• Dennis Kucinich, U.S. Representative from Ohio (Campaign Site)
• Barack Obama , U.S. Senator from Illinois (Campaign Site)
• Bill Richardson, Governor of New Mexico and Former Secretary of Energy (Campaign Site)

Potential candidates:

• Wesley Clark, Former NATO Commander (WesPAC)
• Al Gore, Former Vice President (Al Gore)(Draft Al Gore 2008)

Withdrawn candidates:

• Tom Vilsack, Former Governor of Iowa, a presidential candidate from November 30, 2006 to February 23, 2007, withdrew from seeking the Democratic nomination due to a lack of funds.^[26]

• Sam Brownback, U.S. Senator from Kansas (Campaign Site)
• Rudy Giuliani, Former Mayor of New York City (Campaign Site)
• Mike Huckabee, Former Governor of Arkansas (Campaign Site)
• Duncan Hunter, U.S. Representative from California (Campaign Site)
• John McCain, U.S. Senator from Arizona (Campaign Site)
• Ron Paul, U.S. Representative from Texas (Campaign Site)
• Mitt Romney, Former Governor of Massachusetts (Campaign Site)
• Tom Tancredo, U.S. Representative from Colorado (Campaign Site)

Additional third tier candidates have filed with the FEC - See main article.

Potential candidates:

• Fred Thompson, Former U.S. Senator from Tennessee ('Testing-the-waters' Committee)
• Newt Gingrich, Former Speaker of the House
• Chuck Hagel, U.S. Senator from Nebraska
• Alan Keyes, Former Ambassador to the United Nations Economic and Social Council ^[27]

Withdrawn candidates:

• Jim Gilmore, Former Governor of Virginia, a presidential candidate from December 19, 2006 to July 14, 2007, withdrew from seeking the Republican nomination, citing fundraising problems.^[28]
• Tommy Thompson, Former Governor of Wisconsin and Former Secretary of Health and Human Services, a presidential candidate from April 1, 2007 to August 12, 2007, withdrew from seeking the Republican nomination, citing a poor showing in the Ames Straw Poll held on August 11.