MACKINAC ISLAND, MICH. -- A chill toward the fast-moving presidential campaign of Gov. Michael Dukakis from his fellow Democratic governors gathered at this northern resort reflects two hard questions about his candidacy: Can he carry the South? Is he wrong about free trade?

Dukakis, the first sitting governor (other than George Wallace) seriously seeking the Democratic presidential nomination since Franklin D. Roosevelt, has catapulted to near front-runner status. His performance before the Democratic Governors Association last week outpaced competitors. Yet, only his fellow New Englander, Vermont's Gov. Madeleine Kunin, has endorsed him.

His colleagues rationalize their reticence by saying it is too early. But beneath public explanations is private concern whether Dukakis, a Massachusetts liberal and son of immigrants, can break the Republican stranglehold on southern and western electoral votes. They suspect his regional disabilities are aggravated by stubborn and courageous adherence to free trade.

Nobody else has captured the 26 Democratic governors (19 of whom were here). Apart from Kunin, the only committed governor is Ned McWherter, backing his fellow Tennessean, Sen. Al Gore. But the governors will not stay on the sidelines. Typified by the DGA chairman, Gov. James Blanchard of Michigan, they want to affect the nominating process for a change.

Had Gov. Bill Clinton of Arkansas last month entered the race as expected instead of bowing out as he did, he could have been the DGA candidate. Blanchard was ready to back him, as were Montana's Gov. Ted Schwinden and probably Kentucky's Gov. Martha Layne Collins, perhaps setting off a parade. Clinton is what the governors want: attractive, southern, moderately liberal, nonconfrontational.

Nor does neutrality among the governors stem from inability to sort out the large field. They believe the nominee will come from the eight announced candidates, and almost surely from four of them: two putative front-runners (Dukakis and Rep. Richard Gephardt), a brightening dark horse (Gore) and a fading meteor (Sen. Joseph Biden).

Biden's fade continued here. He refused to attend until Blanchard talked him into it. Permitted to lead off the closed-door session of candidates with governors so he could leave early to work on Judge Robert Bork's September Supreme Court confirmation hearings, his presentation was disjointed.

Gore and Gephardt performed well, but are strangers to the governors. Dukakis is not only well known to them but well liked. He typifies today's Democratic governors: earnest, intelligent, well informed, hard working, humorless, moderate in tone, a little boring. Unlike Mario Cuomo and other gubernatorial superstars, he conscientiously attends governors' conferences.

By eyewitness accounts, Dukakis starred at the closed-door session. He managed an emotional plea for his candidacy with his political peers, outshining Gephardt, who followed him with a businesslike presentation. Yet fellow governors were less than enthusiastic. While they know Dukakis is no McGovern or Mondale doomed in the South and West, they fear his liberalism, ethnicity and appearance are exaggerated by the trade debate he has been drawn into by Gephardt.

The problem was underscored at the National Governors Conference in Traverse City, Mich., preceding the DGA meeting. Most Democrats cheered a protectionist harangue by Chrysler's Lee Iacocca. Gov. Cecil Andrus of Idaho gave Dukakis a Dutch uncle lecture over lunch. Unless he appreciates trade concerns, said Andrus, the Duke would have trouble beyond the Mississippi River.

At Mackinac, Dukakis was not helped by Cuomo. The governor of New York overcame his phobia for conferring with fellow governors when Blanchard prevailed on him to come and stay just long enough for the session with presidential candidates. By body language (stealing peeks at his wristwatch and rubbing his eyes) while Dukakis was speaking, Cuomo showed he is not ready to sign up for his colleague's campaign.

Taking the floor, Cuomo advised candidates not to derogate themselves as ''Snow White and the Seven Dwarfs.'' He warned of regional differences, such as the oil import fee -- the Northeast against it, the Southwest for it -- and suggested Democratic governors could mediate.

Intentionally or not, Cuomo left Dukakis out on a limb as a regional northeastern candidate opposing an oil import fee and facing a debate in Iowa Saturday with Gephardt, who favors it. The Duke may have reason, economics and history on his side. But the tone of his peers at Mackinac was closer to Lee Iacocca and DickGephardt.