WASHINGTON — As the clock ticks toward the end of his presidency and he faces a Republican Congress that is in no mood to cooperate, President Obama on Wednesday kicked off a public-relations campaign aimed at building support for his plans to make college more affordable.

At an event near Detroit, Mr. Obama announced the creation of a national advisory board to push the idea that community college should be free for many students across the country.

“Education has always been the secret sauce, the secret to America’s success,” Mr. Obama said to a small but enthusiastic crowd of students at Macomb Community College in Warren, Mich. “Every American willing to work hard should have a shot at higher education.”

Accompanied by Jill Biden, the wife of Vice President Joseph R. Biden Jr. and a community college professor, Mr. Obama unveiled public-service announcements — featuring students, community college alumni and celebrities — aimed at raising awareness and building support for his plans. Dr. Biden will be one of the advisory board’s two leaders, along with Jim Geringer, a former Republican governor of Wyoming.