(CNN) -- Democratic offices in at least three states have reported instances of vandalism that party members say possibly were tied to Sunday's historic vote on health care reform. Early Monday morning, a glass panel at the Tucson office of U.S. Rep. Gabrielle Giffords, D-Arizona, was shattered, spokesman C.J. Karamargin said. It wasn't clear how the window was shattered, but visitors have to go through a gated courtyard to enter the office, and staffers suspect someone may have shot a pellet gun at the glass, he said. Nothing was taken from the congresswoman's office, Karamargin said. Staffers had stayed late...