1994 casts a big shadow over Democrats in 2010

There are several reasons the Democrats should worry about a repeat of 1994, as reported by the New York Times:

For Democrats, the biggest obstacle appears to be that they are once again working in the kind of environment that has historically proved toxic to the party in power. Mr. Obama’s favorability ratings, like Mr. Clinton’s in 1994, have slipped below 50 percent, almost invariably a bad harbinger for the party in power in midterm elections. Congress and the Democratic Party are today extremely unpopular, as they were in 1994.