Already on the U.S. Senate campaign trail, Duf Sundheim made an unconventional stop Wednesday for a Republican — the Berkeley campus.

Sundheim is vying for the seat that Democratic Sen. Barbara Boxer, the incumbent since 1993, will vacate come January 2017. But he faces tough competition — Attorney General Kamala Harris and U.S. Rep. Loretta Sanchez, D-Garden Grove — and an equally tough crowd at UC Berkeley, a school known for its largely liberal populace.

To promote his candidacy, Sundheim spoke to students in Political Science 179, a lecture that invites guest speakers every week to discuss topics relevant to the field.

“I’m coming just as much to listen as I am to learn,” Sundheim said. “I love to talk with different people, especially with people that don’t ordinarily agree with me.”

The Silicon Valley lawyer is openly pro-choice and aims to modernize public education to better prepare students for the workforce. He also cites the drought as a major concern and hopes to reduce its impact through recycling and desalinization.

Despite his moderate stances, Sundheim said he is aware that he is running in a state in which registered Democratic voters have roughly a 15 percent advantage over Republicans in terms of numbers of registered voters.

“I understand that the biggest negative that I have is the ‘R’ after my name,” he said. “But I’m going to be who I am.”

As of late, Sundheim is trailing in the polls. According to a Field Poll of 694 likely state voters conducted from Sept. 17 to Oct. 4, Sundheim was the first-choice candidate among only 3 percent of respondents.

Two other Republican candidates — Assemblymember Rocky Chavez, R-Oceanside, and former California Republican Party chair Tom Del Beccaro — polled slightly higher.

Harris — a Democrat with a background in law enforcement, beginning with her work as an Alameda County prosecutor — garnered the highest percentage of voter support at 30 percent. Her platforms include education reform and protection of immigrant communities.

“(She) is one of the few people running for U.S. Senate who have held an elected position before,” said TJ Grayson, the political director of Cal Berkeley Democrats. “And so far, she’s done a lot of really good work.”

Seventeen percent of poll respondents selected Sanchez — a Democratic House representative since 1997 — as their first-choice candidate. Sanchez is on the House Armed Services and Homeland Security committees, and is the founder of the Women in the Military Caucus, which works to combat sexual assault in the armed forces.

According to Javiera Cartagena, a spokesperson for Sanchez’s campaign, the representative’s primary concerns are affordable health care, job creation and college affordability.

“She has successfully promoted efforts to improve college access and achievement for all our students, regardless of status or income,” Cartagena said in an email.

The seat that each of the candidates hopes to win has been held for 22 years by Boxer. In an official video released by Boxer in January, she said she plans on returning to her home state from Washington D.C. and continuing to work on her political action committee, PAC for a Change.

While she has not yet endorsed a successor, Boxer said in an interview with Politico that she is happy two women of her party are campaigning for the spot.

“I have to make sure this Senate seat stays progressive — that is so critical,” she said in the video.