In 2012, the Democrats have a whopping 23 seats in the US Senate to defend to the GOP's 10. Politico's David Catanese examines the effect Obama will have on these competitive seats, concluding the President may help effectively kill his own party's Senate majority.

Of the 23 seats Democrats have to defend, five are in states John McCain won. With a paper-thin three seat majority in the Senate, that spells bad news for Democrats in the upper chamber. In two states that Obama lost in 2008, his highly unpopular government health care scheme looks destined to sink Senate Dems chances:

“Nebraska and Missouri are two states in which Obama is more likely to serve as an anchor rather than as a life preserver. In both states, the health care law is deeply unpopular and the two Democratic incumbents are already swimming against the current.”

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