There are certain instances when a judge may be substituted due to cause. However, more frequently, a judge is substituted by right without any other explanation in accordance with 735 ILCS 5/2-1001.
In domestic relations, an attorney may make the recommendation to their client to substitute a judge as a matter of right for any reason prior to any substantive order being entered. Each party is entitled to one substitution of a judge without cause as a matter of right.
A motion to substitute a judge for cause is far more controversial and difficult. If a petition is made to substitute a judge for cause, a motion shall be properly filed and a hearing should occur before a different judge as to whether cause exists.
Removing a judge “for cause,” is not easy. If every party to a lawsuit could make a charge of unfairness against a judge and demand a change, then there would be a constant parade of judges in and out of cases.
Judges are presumed to be impartial and able to put personal feelings and experiences aside when presiding over a case. So to remove a judge for cause, you will have to point to more than just some facts that could possibly lead to bias and unfairness. You have to make the case that this judge is in fact biased against you and you are unable to have a fair trial in front of him or her.