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."
Delmarie Cobb, a Chicago political consultant who worked on Jackson Jr.'s first campaign and was an aide to his father when he ran for president in 1988, said Saturday she was "absolutely astonished" by the news. She, too, believes Jackson Jr.'s actions were triggered by his bipolar disorder.
"It is just not the Jesse Jr. I knew," said Cobb, who's known Jackson Jr. since he was a senior in college and was present when he met Sandi.
"It's a very sad ending for everybody."
Associated Press writers Don Babwin and Tammy Webber contributed to this report.