Former Massachusetts governor and presidential candidate Michael S. Dukakis emphasized the importance of public service to an overflowing crowd of over 150 students Monday night at the Kennedy School of Government.

Dukakis, who challenged former President George H.W. Bush in the 1988 presidential election, encouraged those in attendance to get involved in the political process, even while they’re still students.

“This is the most open political system,” Dukakis said. “Every single one of you should work for a campaign.”

Dukakis, who now teaches at Northeastern, said everyone should also consider future careers in public service, telling students to participate in political internships while in college and then enter fields ranging from politics to education to health and human services.

“There are lots of ways to get deeply involved in public service,” Dukakis said. “I’m not saying everyone has to go out and run for office.”

He described his own route to political success, explaining his first work running for office as he “went out and rang every doorbell.” Both of Dukakis’ parents were immigrants, which many saw as a hindrance when he first entered the political field.

“It was inconceivable in 1962 when I first ran for the legislature that a Greek American could be elected governor,” Dukakis said.

Now he says immigrants and minorities have open access to entering politics.

“The immigrant community is starting to come of age in this country. This is an open door for you,” Dukakis told the crowd, some of whom were students from abroad studying at Harvard for the summer.

But he warned students to make sure they know what field they truly want to enter, saying law school was not a prerequisite for going into public service.

“Don’t go to law school unless you want to practice law,” Dukakis said. “You don’t have to go to law school to be a good politician.”

After his brief speech, Dukakis opened the floor for questions from students, covering topics ranging from his thoughts on the Middle East, the death penalty and the Massachusetts gubernatorial race.

Dukakis criticized the current Bush administration’s handling of the conflict in the Middle East, saying that the U.S. must deal with the conflict between Israelis and Palestinians before worrying about other countries in the region.

“Before we start invading Iraq, we need to get involved in Israel and the West Bank,” Dukakis said.

He said the U.S. should lead the way in “imposing a settlement’’ on the Israelis and Palestinians following the guidelines of the agreement nearly reached at Taba in January 2001, saying the current leadership in the region will not be able to reach a settlement on its own.