It had little to do with policy or strategy, but if there were winners and losers among the six Democratic presidential hopefuls attending the 55th annual Conference of Mayors last week, Massachusetts Gov. Michael S. Dukakis picked up ground and Rep. Richard A. Gephardt (Mo.) lost some.

Gephardt's misstep at the Nashville meeting had less to do with what he had to say than with how long he took: 46 minutes of rhetoric, weak jokes and extemporaneous discussions of issues unrelated to urban problems.

"You just can't talk to a bunch of politicians for that long and expect them to like it," one mayor said.

Dukakis, in contrast, spoke briefly -- about 15 minutes -- and focused on an issue of direct interest to the group, housing.

His proposals were not major innovations, but "he talks in our language of grants, payrolls and programs," one uncommitted mayor said. In addition, Dukakis had a cadre of Massachusetts mayors, led by Boston's Ray Flynn, lining up support.

Meanwhile, Dukakis continues to do well raising money. Robert Farmer, campaign treasurer, said that as of yesterday the campaign had deposited $3 million in the bank and has "every expectation in the next 10 days to add another $500,000." June 30 is the deadline for Dukakis' first quarterly finance report.