Democrats in a struggle to hold onto long-held seats in Congress

Republicans have their sights set on some traditionally secure Democratic seats in the upcoming 2010 midterm elections, via the New York Times:

The fight for the midterm elections is not confined to traditional battlegrounds, where Republicans and Democrats often swap seats every few cycles. In the Senate, Democrats are struggling to hold on to, among others, seats once held by President Obama and Vice President Joseph R. Biden Jr. Democrats are preparing to lose as many as 30 House seats — including a wave of first-term members — and Republicans have expanded their sights to places where political challenges seldom develop.