If Governor Vilsack of Iowa makes it to the White House, it will be thanks in large part to a string of Democrats he has won over from the small farm towns of his home state all the way to Park Avenue.

In a speech this morning at a college near his home, Mr. Vilsack is to become the first major candidate to make a formal announcement kicking off a bid for the Democratic presidential nomination. In terms of timing, the move vaults the governor ahead of the pack, though he has a long way to go to match the national name recognition and fund-raising base enjoyed by better-known contenders, such as the putative front-runner, Senator Clinton.

Mr. Vilsack, 55, plans to travel to New Hampshire tonight and on to Pennsylvania, Nevada, and South Carolina in the coming days. However, in a deliberate nod to his Midwestern roots, the governor gained sustenance for his presidential foray by attending a potluck supper last night in his hometown, Mount Pleasant, Iowa.

In New York, one of Mr. Vilsack’s biggest fans is an investor and generous donor to Democratic causes, Lewis Cullman, who sees the Iowa governor’s base in the American heartland as one of his greatest advantages.

“This guy is a Democratic governor in a red state,” Mr. Cullman told The New York Sun. “To have a Democratic candidate from that section of the country would change the whole dynamics.”

Mr. Cullman, who met the governor through a friend a few years ago, said Mr. Vilsack’s hardscrabble upbringing will also resonate with Americans. “He’s solid. He’s an orphan from Pennsylvania who went out there to Iowa and worked his way up the ladder,” the investor said. The Iowa governor has spoken publicly about being adopted into a home where his mother struggled with alcoholism and he was sometimes abused.

While all the presidential hopefuls have their backers, Mr. Vilsack’s association with Mr. Cullman, 87, could prove quite valuable. In 2004, he gave about $2.7 million to Democratic causes. Mr. Cullman could also be influential because he hails from New York but is dubious about Mrs. Clinton’s chances to make it back to the White House.

“I’m very concerned that she’ll win the nomination but not get elected,” Mr. Cullman said. “In our history only two senators have ever been elected president, Kennedy and Harding. Fifty two have tried and failed.”

In a sense, the Democratic patron said, Mrs. Clinton may be too well known, since many Americans have already decided they won’t support her. “The fact there’s 5% undecided for Hillary is an unheard-of situation. There’s no swing vote there at all,” Mr. Cullman said. “I would hope she would stay in the Senate. She’s doing an absolutely splendid job in New York State.”

The New York Times reported that Mr. Cullman, who endowed the Museum of Modern Art’s just-unveiled education building, said at a museum event last week that he was endorsing Mr. Vilsack for the presidency and a retired general, Wesley Clark, for vice president.

Mr. Cullman told the Sun that he was “quite sure” that he did not specify which man should get which job, since he admires them both. “I said the two of them would make a good team,” Mr. Cullman said. Mr. Clark, who made a hasty run in 2004, is considering another bid for 2008.

A spokeswoman for the Times, Abbe Serphos, said yesterday that its writer recorded the interview with Mr. Cullman and that he answered “Tom Vilsack” when asked whom he was favoring for president.

One of the biggest obstacles Mr. Vilsack faces is that he lacks the experience in national security and military matters that some voters might want in light of the threat of terrorism and the ongoing war in Iraq. “That’s why Wes Clark comes in the picture,” Mr. Cullman said, before arguing that the concern about experience is overblown. “What the hell did George Bush know about foreign affairs” before assuming the presidency? the Democratic donor asked. “You pick a guy you think is a bright, good leader and he can learn and get on-the-job training.”

Whether Mr. Vilsack can gain a home-field advantage in the early and critical Iowa caucuses is in some doubt. “Maybe it’s a wash,” a former aide to Mr. Vilsack, John Norris, said. “He’s the one candidate who can’t get a bump out of Iowa.”

In polls of Iowa Democrats, the governor lags behind Mrs. Clinton and other out-of-state prospects who have cultivated ties in the Hawkeye State, such as the party’s 2004 nominee, Senator Kerry of Massachusetts, and a former senator from North Carolina, John Edwards. There is no sign that Mr. Vilsack is scaring rivals away from Iowa, as another local son, Senator Harkin, did in 1992.

While Mr. Vilsack clearly faces an uphill battle, many political strategists said it would be wrong to count him out at this point. They note that in 1992, a Democratic governor from a small rural state, Bill Clinton of Arkansas, emerged from obscurity to vanquish more experienced rivals and ultimately win the presidency.