In a sequence of events that neatly captures the contradictions of Barack Obama’s rise through Illinois politics, a phone call he made three months ago to urge passage of a state ethics bill indirectly contributed to the downfall of a fellow Democrat he twice supported, Gov. Rod R. Blagojevich. Mr. Obama placed the call to his political mentor, Emil Jones Jr., president of the Illinois Senate. Mr. Jones was a critic of the legislation, which sought to curb the influence of money in politics, as was Mr. Blagojevich, who had vetoed it. But after the call from Mr. Obama, the...