Key activists said the twin decisions would have little impact on the outcome of the caucus, and is a signal of weakness for the two candidates.
"The skipping Iowa strategy hasn't worked in the past," said Iowa Democratic Chairman Gordon Fischer. "I don't see it working this time."
Iowa's precinct caucuses Jan. 19 launch the nominating season, and a large and active field of Democrats has been stumping for months. Lieberman was a relatively late entry into that race, and has campaigned far less than his rivals.
CBS News reports that Lieberman decided to shift resources out of Iowa to be able to compete in New Hampshire and the February 3 primaries, especially South Carolina, South Carolina, Oklahoma and Arizona, where he hopes his centrist message has a better chance of resonating. Lieberman has been running fifth in many Iowa polls and his stand against ethanol did not win him any friends there.
The Connecticut senator called backers Sunday night to tell them he was dropping his campaign efforts in the state, and would likely leave only a storefront operation open with little staff and no campaign time.
Clark spokesman Matt Bennett said there was no way the late-entering Clark could compete with candidates who have been stumping in Iowa for months if not years, and that the retired Army general would not wage an active campaign in the state.
"We have made the decision that we don't have the time or the money to compete there," Bennett said.
Clark New Hampshire chair George Bruno told CBS News that Clark will be spending a lot of time in the Granite State in the next few weeks and expects to compete in the January 27 primary.
Missouri Rep. Dick Gephardt and former Vermont Gov. Howard Dean sit atop the Democratic field in Iowa in most polls, with Massachusetts Sen. John Kerry in third place. Clark and Lieberman fare toward the bottom of the polls.
By opting out of the first test of strength, Lieberman and Clark are following a tactic with a mixed record, and some activists say it may not bode well for their campaigns.
"I think it means they will have to answer hard questions about the status of their campaign," said veteran activist Phil Roeder.
Former Vice President Al Gore opted to skip past Iowa's precinct caucuses in his 1988 bid for the nomination, saying they were dominated by party liberals and opting to make his stand in southern primaries. His campaign quickly faded.
Arizona Sen. John McCain skipped past Iowa in the last election cycle, and defeated then-Gov. George W. Bush in New Hampshire and caused a stir in early tests, but faded from that race.
Veteran activist Joe Shannahan said the candidates' decisions to bow out of Iowa will have little impact on the outcome of the nominating battle.
"Campaigns have to start somewhere, and for now they start here," he said.
Lieberman will open four new offices in New Hampshire that will be staffed in part by redeployed Iowa field operatives, aides said. He'll also add staff in South Carolina, Arizona and Oklahoma.
Lieberman will keep open a storefront office in Iowa with a skeleton staff, but would not longer seriously compete on an organizational basis. The storefront was designed to avoid offending Democrats who had announced backing for Lieberman, sources said.
Lieberman is a leading moderate who supported the war in Iraq, and he is betting that his views will be more acceptable in later tests after Iowa and New Hampshire.