[122][129][130][131] During his 2004 general election campaign for the U.S. Senate, police representatives credited Obama for his active engagement with police organizations in enacting death penalty reforms.[132] Obama resigned from the Illinois Senate in November 2004 following his election to the U.S. Senate.[133]

2004 U.S. Senate campaign
Main article: 2004 United States Senate election in Illinois
In May 2002, Obama commissioned a poll to assess his prospects in a 2004 U.S. Senate race. He created a campaign committee, began raising funds, and lined up political media consultant David Axelrod by August 2002. Obama formally announced his candidacy in January 2003.[134]
Obama was an early opponent of the George W. Bush administration's 2003 invasion of Iraq.[135] On October 2, 2002, the day President Bush and Congress agreed on the joint resolution authorizing the Iraq War,[136] Obama addressed the first high-profile Chicago anti-Iraq War rally,[137] and spoke out against the war.[138] He addressed another anti-war rally in March 2003 and told the crowd "it's not too late" to stop the war.