From The New York Times
Republicans, who need a net gain of only four seats to guarantee control of the Senate, have long been optimistic that they could capture the majority because they are defending just 10 of the 33 seats up for grabs. But their task is complicated by the fact that many of their candidates are sitting or recent members of the House, which polls show to be deeply unpopular.
In the 15 races ranked as most competitive by The New York Times, Republicans could field current or recently departed House members in eight of them; Democratic House members are top candidates in four Senate races.
Races that were not supposed to be all that close are looking more like barn-burners, in large part because one of the standard-bearers carries the millstone of his or her current position: member of the House.
House membership is “more a liability than I’ve ever seen it,” said Stuart Rothenberg, editor of the nonpartisan Rothenberg Political Report. “We go through periods when Congress is less popular than other times, but Congressional approval ratings right now are so abysmally bad, so unbelievably bad, it has to rub off on members seeking higher office.”