With polls showing a drop in Barack Obama’s job rating and sinking support for the Democrats’ health care plans, there is evidence of collateral damage where you might not expect to find it, in the standing of Democratic governors. Pennsylvania’s Ed Rendell is suddenly getting negative job ratings in both the Quinnipiac and the Franklin and Marshall polls — his lowest marks in seven years as governor. Ohio’s Ted Strickland, who has spent most of his first term working amicably with Republican legislators, scores under 50 percent in the latest Quinnipiac poll and has only tenuous leads over two Republicans, John Kasich and Mike DeWine, who may run against him next year.