ABC News' Mark Halperin and Teddy Davis Report: On a conference call with reporters Friday afternoon, former Gov. Tom Vilsack, D-Iowa, said that his decision to end his bid has been "on-going for the last several weeks."
He made his comments after being asked why he is pulling the plug after seeming to operate "full steam ahead" just two days ago when he participated at a Democratic presidential candidates' forum in Carson City, Nev.
Vilsack said that with big states like California, Florida, and Texas thinking about moving up their nominating contests, "you're talking about a significant sum of money: tens of millions of dollars."
In the end, his decision was "ultimately about money."
Asked if he would make an endorsement in the presidential race, Vilsack said, "My focus, my heart and my head is not on endorsements."
There are a number of elected officials who have been for the former governor who are now up for grabs, most especially Sen. Tom Harkin, D-Iowa, who is very close to the Clintons.
Vilsack's wife Christine--whose endorsement of Sen. John Kerry, D-Mass., in 2004 gave him a slight lift among Iowa voters--will likely be a highly sought in the 2008 race.
Several other campaigns will feel the same fundraising pressure Vilsack did throughout the year, particular as the first-quarter fundraising deadline approaches on March 31.
Clinton on Friday issued a statement saying that she and Vilsack share a passion for expanded health-care options, early childhood education, and making higher education more accessible.
Sen. Barack Obama, D-Ill., who opposed the Iraq war before it began, said he appreciates the governor's "passionate advocacy for an end to the war in Iraq."
Of the major candidates, Vilsack had staked out the position furthest to the left on the Iraq war: he wanted to cut off funding for all U.S. fighting in Iraq.