According to this CBS News Poll, if the election were right now, Romney would beat Obama, and the largest margin of loss among all the other Republicans is 8 points.

The Senate (not the House) is still Democrat after 2010 because only a third of them come up for election each time. Had this not been the case, the Senate would not be Democratic now.

Next time around the Democrats are defending 23 Senate seats compared to 10 Republicans. Nine Senators decided not to run for re-election. Seven are Democrats (one technically an Independent) including Ben Nelson, the guy you never heard of. The Republicans need to pick up four seats.

In the House, everyone's up for election each time. That's why the Democrats suffered the highest House loss in a midterm election since 1938. The Democrats will not be getting the House back next time around.

You should "go figure" now and then. It's good exercise.