Q&A: Five key questions about midterm elections in Congress
Why are Democrats in such trouble?
Obama has seen his approval ratings slide well below 50 percent over the summer, while the number of Americans who believe the country is on the wrong track has climbed to above 60 percent in most polls.
Most polls show the sweeping healthcare overhaul passed by Democrats in Congress remains unpopular with a majority of Americans, and public dissatisfaction with congressional Democrats is widespread.
Obama's popularity among independents, a crucial bloc that backed him in 2008, has dipped below 50 percent in many polls, and Republicans are more enthusiastic about the election and more likely to vote than Democrats.
Obama and Democrats got no help from the latest jobless report, which showed the unemployment rate inching up to 9.6 percent.