The days are a blur for Lissa Geiger.

She studies political science at the University of Pittsburgh, tutors refugees in English and campaigns five or six hours a day for Sen. Hillary Rodham Clinton.

This weekend, the last big push before Tuesday's Pennsylvania primary election, Ms. Geiger plans to spend 12 hours a day campaigning.

Ms. Geiger, 20, traces her political activism to eighth grade, when a teacher's choice of posters for a government class seemed to be promoting Republican George W. Bush's candidacy for president. Ms. Geiger, who favored Democrat Al Gore, said the snub only increased her interest in politics and campaigning.

This is her first chance to vote in a presidential election. Ms. Geiger helped organize Pitt students who support Mrs. Clinton. A larger campus group had formed to campaign for the other Democrat contending for the presidency, Sen. Barack Obama.

The popular notion, Ms. Geiger said, was that college students were gravitating toward Mr. Obama, a powerful orator. But, she said, she did not want to cede the Pitt campus to him without a healthy competition.

As she handed out Hillary stickers in front of the William Pitt Union one windy afternoon this week, Ms. Geiger came across an acquaintance, Pitt sophomore Stephanie Luczajko.

Ms. Geiger asked her if she would be voting for Mrs. Clinton.

"I'm leaning toward Obama," Ms. Luczajko said.

Ms. Geiger, a scholarship debater at Pitt, had a fast comeback. She asked Ms. Luczajko if she might be interested in attending graduate school one day. Ms. Luczajko said she might.

Then Ms. Geiger outlined Mrs. Clinton's plan to make college more affordable. Ms. Geiger called it the most comprehensive of any candidate's because it would extend to graduate schools.

Later, Ms. Luczajko said the conversation gave her something more to consider, though she was still inclined to vote for Mr. Obama.

Pitt student Ian Lauer described Ms. Geiger as a tireless worker, rushing from the campus in Oakland to Downtown Clinton headquarters to help with phone banks, Internet announcements or whatever chore is asked of her.

"Lissa, she's in this 100 percent," Mr. Lauer said.

He met Ms. Geiger through the Pennsylvania Federation of College Democrats. She is president of Pitt's chapter.

Ms. Geiger, who grew up in Mechanicsburg, Cumberland County, said the values of the Democratic Party fit with her own.

These include lending a hand to the underrepresented and the underprivileged. Ms. Geiger puts these concepts into practice, tutoring students at Pittsburgh Schenley High School who are learning English as their second language. She also volunteers with adults, helping them prepare for General Educational Development tests so they can obtain the equivalent of a high school diploma.

Mrs. Clinton, she said, practiced such activism and highlighted education as one of America's most important issues in her book, "It Takes a Village."

Ms. Geiger has read two of Mrs. Clinton's books and one of Mr. Obama's, "Dreams From My Father."

She said she likes Mr. Obama well enough, but concluded that Mrs. Clinton was the superior candidate.

"Her ideas speak to me more," Ms. Geiger said.

Chief among them are affordable universal health care and the belief that education is the key to success.

Ms. Geiger said she thinks Mrs. Clinton, now trailing Mr. Obama in pledged delegates and popular votes, can still win. The formula is to finish strong in the remaining primaries and overtake Mr. Obama in the overall popular vote.

Ms. Geiger's distaste for the likely Republican presidential candidate is palpable.

"I would never vote for [Sen.] John McCain. His admitted lack of understanding of the economy is only one reason," she said.

Ms. Geiger has met Mrs. Clinton just once, a momentary exchange that produced a handshake. But the candidate is always on her mind. Ms. Geiger wears two "Hillary" buttons on her jacket and studies Mrs. Clinton's positions and her biography.

Ms. Geiger says Mrs. Clinton's commitment to people motivates her. She recalls how Mrs. Clinton, while still single in 1973, became a staff attorney for the Children's Defense Fund, an organization that paid special attention to the poor.

Mrs. Clinton could have taken a higher-paying or more visible job, but opted for one that helped those who needed it most, Ms. Geiger said. She said this spirit can energize the country, just as it inspired her to join the campaign.