"Now that Democrats control the White House, Congress and most governorships, voters' discontent with the status quo represents their burden, which has Democratic strategists considering tactics to push back challengers," the New York Times reports.
Said pollster Geoff Garin: "Very often the instinct for an incumbent party is to defend and justify. But in this kind of environment, the best defense is a good offense. This needs to be a cycle where Republican vulnerabilities are a central part of the debate."
Charlie Cook puts it more bluntly: "They're going to have to play really rough. For the average Democratic Congressional incumbent, the opposition researcher will be the most important person in the campaign."