To gain control of the Senate, Republicans need to pick up six seats. Political analyst Stuart Rothenberg says they’ll do at least that. “I am now expecting a substantial Republican Senate wave in November, with a net gain of at least seven seats,” Rothenberg writes. “But I wouldn’t be shocked by a larger gain.” Specifically, he expects Republicans to pick up Montana, South Dakota and West Virginia, while Democrats should consider Arkansas and Louisiana “difficult to hold.” Alaska and North Carolina are still close, but, he says, “after looking at recent national, state and congressional survey data and comparing this election cycle to previous ones … the signs are ominous” for Democrats. Why? Two words: Barack Obama. The president’s approval rating is at an all-time low, and voters’ dissatisfaction with his leadership is bleeding over to his fellow Democrats. “With the president looking weaker and the news getting worse,” Rothenberg concludes, “Democratic candidates in difficult and competitive districts are likely to have a truly burdensome albatross around their necks.” More…