In Northampton County, all four judges elected in the past 10 years -- Beltrami, Edward Smith, Emil Giordano and Paula Roscioli -- have presided over at least one donor's case, court records and campaign reports show. In Lehigh County, Maria Dantos and J. Brian Johnson have as well.

The instances underscore how judicial rules basically leave it up judges to decide whether they should recuse themselves from a case. They also demonstrate how Pennsylvania's system of electing judges leaves the bench vulnerable to claims of one-sidedness or worse, even though the donations are legal.

A USA Today/Gallup poll found in February that nearly 90 percent of Americans believe the influence of campaign contributions on judges' rulings is a problem. Reform groups argue that the perception harms the court, an institution that is supposed to be an impartial arbiter.

''Think about yourself being in court and sitting and wondering whether your opponent or your opponent's attorney made a large contribution to a judge,'' said Lynn Marks, the executive director of Pennsylvanians for Modern Courts.

In 2007, Dantos was a recently appointed Lehigh County judge and hoping to be elected to her own 10-year term on the bench. As a judge, she was presiding over a medical malpractice suit against Lehigh Valley Hospital. As a candidate, she was receiving $1,500 from the hospital's top official.