A reliable liberal, Jackson voted with the Democratic caucus 97 percent of the time. He joined House Democrats in pushing for the impeachment of George W. Bush over his handling of the Iraq war, opposed the 2008 financial industry bailout and fought to abolish the Electoral College and for a constitutional amendment guaranteeing high-quality public education for all U.S. citizens.
December, 2004: Jackson undergoes a surgical procedure known as a "duodenal switch" that removes a large section of his digestive tract and helps him lose weight. He did not publicly disclose the surgery until several months later, saying in a 2005 interview that he lost 50 pounds through a strict diet. Observers initially speculated that Jackson's later diagnosis of bipolar disorder was tied to his surgery, but doctors denied those suggestions.
During the 2008 presidential campaign cycle: Jackson was an early supporter of then-Sen. Barack Obama's presidential campaign and bucked the advice of his father and senior members of the Congressional Black Caucus who backed Hillary Rodham Clinton.
As Paul Kane wrote, Jackson's support for Obama "wasn't just about passing the torch to the next crop of black leaders; it was also about Jackson's ambition. By the summer of 2008, he was among a handful of Illinois politicians courting the Senate appointment as Obama secured the nomination and then took a commanding lead in the general-election campaign."
April, 2009: Jackson announces that he's the subject of an Office of Congressional Ethics inquiry into his role in attempting to succeed Obama in the Senate. Jackson was referred to in the media as "Candidate A" in the April 2, 2009, indictment of then-Illinois Gov. Rod Blagojevich, D-Ill., which alleged that a Jackson emissary discussed raising money for the governor in exchange for promoting Jackson to the Senate seat.