Next Tuesday Democrats will receive a crushing rebuke. More to the point, voters will be delivering a verdict on the first two years of the Obama administration.

Midterm elections are almost always unpleasant experiences for the White House, especially when the economy is weak. But key races that should have been safe for the party in power demonstrate the extent to which President Obama and his policies have nationalized the election.

In Nevada, Senate Majority Leader Harry Reid has a huge war chest in a state Mr. Obama won in 2008 by 12 points. Mr. Reid trails Sharron Angle by four points in the latest Rasmussen poll...