I realized yesterday that conservative talk show hosts like Rush Limbaugh and Sean Hannity really want the Democrats to stay in power. They want a Democrat in the White House, and they want Democrats controlling as much of the federal government as possible. It makes their jobs a lot easier because they can just take any action by the Democratic leaders and denigrate and ridicule it.
When Republicans are in power, they don't have a readily available scapegoat for political problems. Ridiculing the Right would look foolish, since that's what they supposedly stand for (not that they seem to care about looking foolish), but continuing to harp on the left would make them look like bullies, and no one likes to see someone getting kicked when they're down (not to mention it would look even more foolish to keep blaming the people who aren't the one's in power). So they end up with tougher jobs and have to actually put some effort into their shows.