"We must not allow our lead over the [National Republican Congressional Committee] or successful recruiting efforts to lull us into a false sense of complacency," he wrote. "Historically, following a wave election like 2006, the majority party loses seats. We can beat this historical pattern, but only if we maintain our political momentum and stay focused on our agenda of change."
In particular, Van Hollen raised the threat of Republican 527s that could spring up and counter Democrats' fundraising edge. He mentioned Freedom's Watch, Republican billionaire Sheldon Adelson and Tom DeLay as potential threats.
Van Hollen wrote that he was "increasingly hopeful" that Democrats would pick up seats in November.