[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2009/images/10/22/art.cvanhollen.gi.jpg caption="Chris Van Hollen warned fellow Democrats that they are heading into a challenging midterm election."]
WASHINGTON (CNN) - Maryland Rep. Chris Van Hollen warned fellow Democrats Thursday that they are heading into a challenging midterm election, but assured them that everything is being done to head off major losses in 2010.
"Historically, we're facing a headwind this cycle with a record number of Frontline Members, a smaller playing field of challenger races, and a difficult fundraising environment," Van Hollen wrote in a six-page memo sent to House Democrats and obtained by CNN. "We've known about that challenge from the start and have been aggressively preparing for it, applying the lessons from the last two successful cycles."
Van Hollen, chairman of the Democratic Congressional Campaign Committee, points to 20 Republican seats that he thinks can turn Democratic in 2010. Of those 20, Van Hollen singled out open seats in Delaware, Illinois and Pennsylvania, as well as the Louisiana seat held by GOP Rep. Joseph Cao, as "four strong pick up opportunities."
"As we discussed at the beginning of this year, after House Democrats' big wins over the past two cycles – 54 seats in some of the reddest districts in the country – our best defense this cycle is a strong offense," Van Hollen wrote.
Despite Democratic fundraising success and Van Hollen's analysis that the GOP is a damaged brand, he conceded that historical trends run against the party. "Since Abraham Lincoln's Presidency, 22 of 24 newly elected Presidents saw their party lose seats in Congress in the following midterm election," he said.
And because of the challenge facing Democrats in 2010, Van Hollen urged his colleagues to become involved in helping to preserve their majority in the House.
"We need every Member of our Caucus to pitch in," he said.