Former Rep. James V. Stanton of Ohio became the fifth Democrat to enter the race for national party chairman on Tuesday, saying he represents none of the party's factions and could unify it for the 1992 presidential campaign.

Stanton, now a Washington lawyer, entered the race acknowledging he trails some of the other candidates."I believe I can revitalize the party structure and bring all Democrats under the same roof," he said at a news conference. "I am uniquely qualified to do this because I am not the candidate of the South or the candidate of the Northeast, or the candidate of the right or the left."

The nearly 400 voting members of the Democratic National Committee will select a new national chairman when they meet in Washington Feb. 9-10.

Already in the race are Ron Brown, a former aide to Jesse Jackson; Richard Wiener, Michigan state party chairman; former Rep. James Jones of Oklahoma, the former chairman of the House Budget Committee, and former Rep. Michael Barnes of Maryland.

Stanton has the backing of former House Speaker Thomas P. O'Neill of Massachusetts, although O'Neill does not have a vote on the committee. He is backed by his state's two Democratic senators, John Glenn and Howard Metzenbaum, but his Ohio party leaders have endorsed Wiener.

Stanton said he expected to compete with Brown for organized labor's votes on the committee, and he called Wiener "obviously the insider" in the race.

He said he would concentrate on party building and fund raising as chairman. He dismissed Jones' proposals for building a permanent staff of campaign professionals to be folded into the eventual presidential nominee's campaign, and said he had no plans for changing delegate selection rules.

"There are many people who want to tinker with the machinery of the Democratic Party. I'm not one of them," he said.

Stanton is a former Cleveland City Council president who served three terms in the House before losing the 1976 Democratic Senate primary to Metzenbaum.