CHICAGO (AP) - For all the talk of Jesse Jackson Jr. aspiring to be a U.S. senator or mayor of the nation's third-largest city, his career wasn't ended by attempts to amass political power. Instead, it was the former congressman's desire for flashy items - a gold-plated Rolex watch, furs and collectibles, such as Eddie Van Halen's guitar. In a state where stop-at-nothing political ambition has been well documented - and often rewarded - the seemingly frivolous cause of Jackson's undoing is seen by political observers and at least one former colleague as both nonsensical and sad. "When you have a magic name like that, he was in position, waiting for the gun to go off, for mayor, the Senate ... he was playing with the big guys." said Paul Green, a longtime political scientist at Roosevelt University in Chicago who moderated Jackson's first congressional campaign debate. To go down for this, you just feel sad. Federal prosecutors on Friday charged Jackson Jr. with one count of conspiracy for allegedly spending $750,000 in campaign money on personal expenses. The Chicago Democrat's wife, former alderman Sandra Jackson, was charged with one count of filing false joint federal income tax returns. Authorities say the returns, for the years 2006 through 2011, knowingly understated the income the couple received. Their sentencing dates have not been set, but the charges both carry possible sentences of several years in prison. Jackson Jr. also could be ordered to repay thousands of dollars in fines and forfeitures. While former Illinois Gov. Rod Blagojevich went to prison because he tried to trade President Barack Obama's U.S. Senate seat for a more prestigious job or millions in campaign donations, Jackson could go to prison for, in part, buying memorabilia tied to martial arts movie star Bruce Lee. The son of a civil rights icon, Jackson represented Illinois' 2nd District, which includes part of Chicago's South Side and south suburbs, for 17 years. He was wildly popular in his heavily Democratic district, consistently winning elections with at least 80 percent of the vote. Jackson served as national co-chair of Obama's presidential campaign in 2008 and had his eyes on becoming mayor or a senator. But those hopes were dashed when his name surfaced as part of Blagojevich corruption investigation and with revelations that Jackson had been involved in an extramarital affair. Jackson denied any wrongdoing in the Blagojevich matter, which involved unproven allegations that he was involved in discussions to raise campaign funds in exchange for being appointed to Obama's vacated U.S. Senate seat. Suddenly last summer, Jackson disappeared from public view for several weeks. His staff eventually revealed he was being treated for bipolar disorder and other medical issues. When Jackson resigned from office in November, he cited his bipolar disorder and acknowledged he also was under federal investigation. Sandi Jackson resigned from her Chicago alderman seat in January. U.S. Rep. Danny Davis, who represents a neighboring district and visited Jackson Jr. shortly after his release from treatment at the Mayo Clinic, said the charges against the Jacksons "couldn't be more unfortunate." "I think things probably just got out of hand for them and they got involved in making decisions that just didn't make a lot of good sense," Davis said. Davis wondered whether the long list of luxury purchases mentioned in the federal criminal complaint were "an indication that his bipolar condition kind of was manifesting itself even then." If so, he said, it's unfair to compare this situation to other Illinois corruption. "It's hard to rationalize it," Davis said. Not all elected officials in Illinois are corrupt or building any kind of political dynasty or trying to develop political power. Most individuals elected to public office are citizens who want to make the most effective use of themselves and make this world a better place in which to live. Associated Press writers Don Babwin and Tammy Webber contributed to this report.