Dr. Tim Robinson is giving Sen. Jim Brochin the toughest challenge he's faced since the Democrat was first elected to the legislature 12 years ago. Dr. Robinson, an anesthesiologist and long-time friend of U.S. Rep. Andy Harris, is running a vigorous campaign and benefits from a district that was re-drawn by State House Democrats to favor a Republican challenger to Senator Brochin. Dr. Robinson talks up the lack of philosophical competition in a General Assembly dominated by Democrats and points to the increased taxes and spending of the O'Malley years as proof that the state needs a change. His strongest issue, though, and one on which his views are not particularly partisan, is his ability as a physician to bring expertise about the health care system that has been missing a doctor's voice since Mr. Harris was elected to Congress. As he correctly notes, the state's medical system will see great changes in the years ahead as a direct and indirect result of the Affordable Care Act, and it would be useful to have a doctor in the Senate to help parse the choices ahead.