With many still digesting the results of the midterm elections, Governor Vilsack of Iowa pushed the political clock forward by jumping into the contest for the Democratic presidential nomination in 2008.

Other Democrats have signaled that they expect to make presidential bids, but Mr. Vilsack is the first major candidate to establish an official campaign committee and open a staffed campaign headquarters.

“I’ve never started a race that I’ve been expecting to win — and I’ve never lost,” Mr. Vilsack, 55, said in a video message posted on his new presidential campaign Web site. “Being an underdog doesn’t bother me. I’m very comfortable in that position.”

“Underdog” may be an understatement. In a poll taken on Election Day by McLaughlin & Associates, Mr. Vilsack had no measurable support among registered Democrats. Leading the pack of potential Democratic contenders was Senator Clinton of New York, with 31% support, followed by Senator Obama of Illinois, with 19%.

Mrs. Clinton has made no public announcement about a presidential campaign, though she has been carefully laying the groundwork for such a bid. Mr. Obama said he has thought about a run for the White House and will make a decision in the coming weeks. They are just two of a gaggle of Democratic senators who are considering jumping into the race, including senators Biden of Delaware, Dodd of Connecticut, Feingold of Wisconsin, and Kerry of Massachusetts.

With all the Capitol Hill talent expected to enter the contest, one of Mr. Vilsack’s major selling points is likely to be his status as a Washington outsider and a product of the American heartland. “My view is there are actually more solutions on Main Street America than in K Street,” he declared in his announcement video.

“He brings an outside Washington perspective. He brings executive branch experience,” a former chief of staff to Mr. Vilsack, John Norris, told The New York Sun. “If you look at the crowded field, there are few with that combination, if any. … I think he starts with two arrows in his quiver that no one else has.”

Mr. Vilsack’s chances got something of a boost last month when a former Virginia governor who had also positioned himself as a Washington outsider, Mark Warner, declared that he would not seek the White House. The only other state official expected to enter the Democratic presidential sweepstakes, Governor Richardson of New Mexico, served 15 years in Congress.

Mr. Vilsack will join other candidates looking to establish themselves as an alternative to Mrs. Clinton, who is seen as the Democratic front-runner. Mr. Norris said he does not expect his former boss to stoke concerns that some Democrats have expressed about Mrs. Clinton’s ability to win the general election. “I think Vilsack and others will allow the Hillary questions and the situation to play itself out without having to get into it themselves,” Mr. Norris said.

One of the most compelling aspects of Mr. Vilsack’s candidacy may be his personal story. Orphaned at birth in Pittsburgh, he was put up for adoption by Catholic Social Services. The governor has said his adoptive mother struggled with alcohol and drug problems and that the home environment was sometimes abusive.

While Mr. Vilsack emphasizes his roots in middle America, he also has some New York ties. As an undergraduate, he attended Hamilton College in upstate Clinton. He earned his law degree from Albany Law School in 1975. He later moved to his wife’s hometown in Iowa and went into law practice with his father-in-law.

Mr. Vilsack, who is to leave office in January after serving two four-year terms, has established a reputation as a centrist and he currently heads the Democratic Leadership Council, which helped catapult a governor from Arkansas, Bill Clinton, into the presidency. However, there are few areas where Mr. Vilsack has broken with Democratic Party orthodoxy. The only obvious example is his decision to appease anti-immigration forces by signing a largely symbolic bill declaring English to be the state’s official language.

Mr. Vilsack enjoys a strong relationship with labor unions and recently brokered a truce of sorts between Democratic Leadership Council officials and labor leaders, according to a liberal magazine, the American Prospect. A former aide to Vice President Gore, Christopher Lehane, said labor groups would give serious consideration to supporting the governor, particularly if Mrs. Clinton falters or decides not to run. “They’ll take the phone calls. They’ll sit down with him,” Mr. Lehane said.

One challenge facing Mr. Vilsack is skepticism on the part of voters in his home state. In a survey of Iowa Democrats taken in June, he came in fourth behind a former senator from North Carolina, John Edwards, Mrs. Clinton, and Mr. Kerry.

“Vilsack is a long shot and I assume he’s well aware of that,” a political science professor at the University of Iowa, Peverill Squire, said. He said many Iowans doubt that the governor can gain the national stature needed to win the nomination. Some think Mr. Vilsack is positioning himself as a possible vice presidential pick, the professor said.

While Mr. Vilsack lacks the national security experience that could be important in dealing with issues such as terrorism and Iraq, he does have a serious, executive air. A veteran Democratic operative, Joseph Trippi, said the governor impressed the national elites gathered last winter for a retreat known as Renaissance Weekend. “He really wowed that place and it’s a tough place to wow,” Mr. Trippi said. “He just clearly had thought about a lot of issues.”

Mr. Trippi, who ran Howard Dean’s presidential campaign in 2004, said Mr. Vilsack has to build his reputation in other early primary states, such as New Hampshire and South Carolina, to convince Iowa voters that he’s viable. “He’s going to have to score outside Iowa before he can score in Iowa,” the consultant said.