ABC News’ Tahman Bradley reports: Rep. Chris Van Hollen, D-Md., warned liberal interest groups on Wednesday that they should not target moderate Democrats who’ve staked out positions opposing some of President Obama’s agenda. Van Hollen, who’s tasked with getting Democrats elected to the House of Representatives in his capacity as chairman of the Democratic Congressional Campaign Committee, is the second Democratic leader in a week to ask the groups to ease up on party moderates. "What I’ve been reminding people very clearly is (to) beware of forming a circular firing squad," he told reporters at a briefing. "We believe people should focus their efforts on expanding a Democratic majority and that should be their singular focus." Van Hollen pointed to the defeat of Republican Wayne Gilchrest in Maryland’s first congressional district GOP primary last year as a sign of what can happen when interest groups set their sights on members who are not in lockstep with the party. The anti-tax group Club for Growth aired TV ads against Gilchrest and backed his opponent in the GOP primary. Gilchrest lost the primary battle, and Democrats went on to win the seat in the general election. MoveOn.org, Americans United for Change and ACORN have been running ads targeting moderate Democrats in the House and Senate who oppose Obama’s budget and other proposals. Prominent Democratic members of the Senate like Evan Bayh of Indiana, Blanche Lincoln of Arkansas, and Tom Carper of Delaware, have been targeted by the groups. Senate Majority Leader Harry Reid, D-Nev., told reporters last week that he viewed the ads as "unwise and unhelpful." Even President Obama reportedly is worried about what would happen to Democrats if they turn on one another. A recent National Journal article by Brian Friel quoted a participant of a closed-door meeting between President Obama and Senate Democrats on March 25 as saying the president warned moderates that Democrats will do well in 2010 if voters view him as an effective president. "If we don’t get health care, and we don’t do energy, and we don’t take care of these priorities," the president said, according to the participant quoted by National Journal, "I don’t care how far you distance yourself from me. I don’t care how many times you say I’ve gotten too liberal, it’s just not going to do you any good. It’s just not going to help you any." Van Hollen said he’s spoken to certain groups about changing their focus. ABC News’ Teddy Davis contributed to this report.