Conflict of interst? What conflict of interest?

"During Tuesday’s hearing, the judge, Thomas M. Durkin of the Federal District Court for the Northern District of Illinois, acknowledged what some people have viewed as potential conflicts: He donated $1,500 to Mr. Hastert’s campaigns in the early 2000s; had worked alongside Mr. Hastert’s son Ethan; and is the brother of Jim Durkin, the Republican leader of the Illinois House."