Allan J. Lichtman, a Bethesda Democrat and history professor at American University, declared his candidacy for the U.S. Senate yesterday, portraying himself as an alternative to conventional politicians, including those in his party.

Lichtman, who has never held office, will compete for the party's nomination in a field of candidates that includes Rep. Benjamin L. Cardin (D-Md.) and former congressman and NAACP leader Kweisi Mfume.

Speaking at North Bethesda Middle School, where his son is a student, Lichtman directed some of his remarks toward Cardin, whom he said he perceives as the front-runner. "Some say in this election, we must unite behind an anointed front-runner," he said. "But we know the anointment model has never worked in Maryland. Anointment is a recipe for nothing more than a Republican senator in 2006."

The other Democrats who have announced their intention to replace retiring Sen. Paul S. Sarbanes (D-Md.) are Lise Van Susteren, a forensic psychiatrist and sister of Fox News anchor Greta Van Susteren, and A. Robert Kaufman, a Baltimore community activist. Others could emerge before the deadline in July.

On the Republican side, party leaders are rallying around Lt. Gov. Michael S. Steele, who has formed an exploratory committee to consider seeking Maryland's first open Senate seat in two decades.

Kevin Zeese, a Takoma Park political and social activist, has announced an independent bid.

As Lichtman spoke to a small group of supporters in the school's gymnasium, more than 20 students stood behind him carrying signs that read: "He's Our Man. He's Allan Lichtman," and "If You Have a Brain, Vote for Lichtman."

Lichtman, 58, a father of two and native of Brooklyn, N.Y., criticized the Bush administration for getting too involved in what he said were personal matters, such as the Terri Schiavo case.

"I am running to change what is wrong in Washington," Lichtman said. "My friends, today there is too much government intruding in our private lives and not enough government meeting our needs."

Calling the war in Iraq "deceptive," he urged President Bush to pull out U.S. troops by the end of next year. He also said that, if elected, he would draft legislation to reduce the country's dependence on fossil fuels by 50 percent over 20 years.

To help finance his campaign, he has mortgaged his house, he said.

"There is too much government intruding in our private lives and not enough government meeting our needs," Allan J. Lichtman told supporters.