Steve Grossman, a former chairman of the Democratic National Committee, dropped out of the Massachusetts governor's race on Friday.

"As a practical businessman, I understand victory in the primary is not in the cards for me this year," Grossman said in a statement announcing his decision.

His departure leaves four Democrats vying for the nomination: former Labor Secretary Robert Reich, State Treasurer Shannon O'Brien, former state Sen. Warren Tolman and state Senate President Thomas Birmingham.

Mitt Romney, the former Salt Lake City Olympics chief, is the Republican party's candidate. Acting Gov. Jane Swift, a Republican, dropped out of the race in March.

Grossman, 56, had had poor showings in statewide polls despite the support of former President Clinton, who stumped for him even though Reich, Clinton's former labor secretary, was also vying for the nomination. As a party fundraiser, Grossman had raised hundreds of thousands of dollars for Clinton's campaign.

Grossman served as Democratic National Committee chairman from 1997 to 1999 and headed the state Democratic Party in 1991 and 1992. He is president of MassEnvelopePlus, a family-owned printing company.

Campaign spokeswoman Alex Zaroulis said Friday that a recent internal poll showed Grossman trailing both O'Brien and Reich.