United States presidential election, 2008: Illinois Senator Barack Obama wins the Wyoming Democratic caucus.
Senator Barack Obama beat Senator Hillary Rodham Clinton by a wide margin, continuing his string of victories in caucus states.
- The New York Times
- United States presidential election, 2008: Illinois Senator Barack Obama wins the South Carolina Democratic primary.
- Australian Prime Minister John Howard criticizes U.S. Senator Barack Obama (D-IL) for his stance on Iraq, saying that al-Qaeda in Iraq should be praying for Obama to win the election. The opposition Australian Labor Party says that Howard's statement imperiled the relationship Australia might have with the United States under a Democratic administration.
- United States presidential election, 2008: Senator Barack Obama (D-IL) officially announces his candidacy for president during a speech at the Old State Capitol in Springfield, Illinois.
- Democratic Illinois Governor Rod Blagojevich is arrested by Federal Bureau of Investigation agents at his Chicago home, amidst allegations of corruption and pay-to-play regarding the replacement for United States President-elect Barack Obama in the Senate.
- Illinois Senator Barack Obama wins the Democratic Party presumptive nomination, becoming the first African American to be nominated by a major party.