GRINNELL, Iowa - For Barack Obama, this has been College Week in Iowa, which might seem an odd use of his time.

The Democratic presidential candidate has long since established himself as the darling of the college set. His on-campus crowds are invariably huge and adoring, his receptions rapturous.

But Obama has a problem. On caucus night, Jan. 3, schools will be out of session, and many of his young backers will be scattered all over the place.

"I would love to be here," said Aki Shibuya, 18, a Grinnell College freshman from Orinda, Calif., who is volunteering in the Obama campaign. "But Mom and Dad want me home. I guess I'll be here in spirit."

With that in mind, the Illinois senator made the rounds this week, stopping at six campuses in four days, ranging from the big state universities to the tiny liberal arts colleges, talking logistics, boosting spirits and urging participation.

Late Tuesday night, at the cavernous old field house at the University of Iowa, an estimated 3,000 students turned out to get their marching orders.

"If you are from Iowa originally, and you're going to be back home on Jan. 3, then I want you at home caucusing for me," Obama said, striding the stage in front of a huge American flag. "I don't just want you. I want your parents, your friends, your siblings, Uncle Jethro. Take them to the caucuses with you."

The way the first-in-the-nation caucuses work, his student-supporters probably are more valuable to him in their Iowa hometowns, if they turn out; he'll probably sweep the college towns without them anyway.

At Grinnell, where 85 percent of the 1,600 students are from other states, his emphasis was a little different.

"Many of you are going to be gone on Jan. 3, but many of you are going to come back," he said. "I want you to come back."

Not everyone in the high-stakes caucus battle wants the out-of-state students to participate. The Clinton campaign, in particular, has suggested there is something inappropriate about it, saying the Iowa caucuses should be left to true Iowans.

But state officials say it's perfectly legal for students to claim their college address as their voting residence, and Obama purports to be miffed that anyone would think his strategy improper.

"I don't exactly understand what the problem is," he told student crowds on several occasions. "I thought it was our civic duty to try to get everyone involved. Don't let anyone tell you that you can't participate."

Efforts are being made at several schools to get some out-of-state students back for caucus night, regardless of whom they support.

At Grinnell, for instance, both the Obama campaign and the college Democrats are trying to organize car pools from places such as Chicago, St. Louis and Minneapolis.

The school is opening the athletic center for the night of Jan. 3, giving returnees a place to spread out their sleeping bags. While the dorms will remain closed until the semester resumes Jan. 21, students who live off campus are being urged to open their doors.

"I'm coming back," said Sally Blatz Durivage, 22, a Grinnell senior, who plans to make the five-hour drive from her home in Evanston, Ill., on Jan. 3 and then go right back on Jan. 4. "It's exciting for me, having watched him in Illinois. But I don't think you'll see too many people coming from outside of driving distance."

On his college tour, Obama, who is engaged in a tight race here with Sen. Hillary Rodham Clinton of New York and former Sen. John Edwards of North Carolina, has done more than talk about how students can participate.

At Cornell College yesterday, Obama delivered a speech on national service, calling for expanding AmeriCorps from its current 75,000 slots to 250,000, and doubling the size of the Peace Corps, among other things.

In addition, he has been taking his shots at the Clinton campaign - "the old textbook campaign," he calls it derisively - even though he rarely mentions his rival by name and usually lets his aides respond to the more direct criticisms she has been leveling at him.

"When I am the Democratic nominee, my opponent won't be able to say that I voted for the war in Iraq because I didn't," he told a rally at Iowa State University in Ames a few days ago, "won't be able to say I gave George Bush the benefit of the doubt on Iran because I haven't, won't be able to say that I support the Bush-Cheney policy of not talking to leaders we don't like because I don't."

Regardless of how many college students show up on caucus night, Obama has assembled a huge organization - he has 37 offices around the state - and has won the backing of plenty of Iowans who are not college students.

"He's the first person in many, many years who's caught my attention, because of his clarity, his honesty and his principles," said Cyndy Newton, 53, a nurse who lives in Ames. "I believe that he is the one person who will turn heads again in the international community. I think we've become a nation of embarrassment, and I think he can change that."

And he has yet to play the Oprah card. Winfrey might not be big among college students. But she's popular with lots of other people. She will be in Iowa on Saturday, asking Iowans to caucus for Obama.

Read Larry Eichel's previous stories and other coverage at

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Contact senior writer Larry Eichel at 215-854-2415 or leichel@phillynews.com.