An aide to Burlington Mayor Bernard Sanders went to the basement of City Hall recently to preview an exhibition of Hiroshima pictures that were to go on display during the visit of a prominent anti-nuclear activist. He was horrified.

The pictures were ghastly. They depicted a blasted city and close-up views of the charred, twisted bodies of men, women and children. Hung on the walls of City Hall, they would be not only a commentary on nuclear war but a condemnation of the U.S. decision to drop the atomic bomb.

Aides urged Sanders not to allow the pictures to be hung for fear it would hurt him in today's municipal elections. Sanders did it anyway, although he cut the display time.

Those who have watched him for the last two years were not surprised. For Sanders, one of a tiny handful of socialist mayors in the country, is a committed radical, as dedicated to the remaking of American society as to providing competent administration to a city that had not seen it for years.

The question is whether the conservative voters of this small city of Victorian homes on Lake Champlain will vote for a dedicated enemy of the "establishment" and the capitalist system. A favorite line here is, "As goes Burlington, so goes France."

As the election approached, Sanders did not play down his radical ideology, although he stressed his administrative changes.

A Brooklyn native with a political science degree from the University of Chicago, Sanders, 41, was perceived as a fluke when he was elected in 1981 by 10 votes out of more than 9,000 cast.

The Republicans failed to put up a candidate against the five-term incumbent Democrat, and Sanders appeared to be the beneficiary of a protest vote.

The outcome this time will be no fluke. The Republican candidate is a local businessman, James Gilson, and the Democrats have put up state Rep. Judith Stephany. All three campaigns are better financed than any have been in the past.

An early poll showed Sanders with 100 percent name recognition and a 73 percent favorability rating, and subsequent straw polls showed him with a comfortable lead.

His problem is that if he gets less than 40 percent in the three-way race, it will force him into a runoff.

Even many who oppose Sanders concede that he has been an excellent mayor. His cleanup of the city's financial affairs resulted in savings of as much as three-quarters of a million dollars annually, a significant accomplishment in a city with a $22 million budget.

He put the city insurance coverage out to bid, introduced central purchasing, conducted the first audit of the city employes' pension fund, discovered $1.9 million tied up in mis-designated accounts and reinvested the city's funds, previously held in checking accounts and low-interest passbook savings accounts, to get a higher return.

Nevertheless, his opponents contend that he is anti-business, and that he is likely to turn more sharply to the left if he is reelected. As one prominent Republican put it:

"Bernie works all the time, he is impeccably honest, he is sincere, he has lots of charisma . . . . As a mayor, he has done a pretty damn good job. The bad thing about Bernie--and why I don't think he will get reelected--is that they are always going to hold his socialist views against him, his confrontational style, the fact that he insulted everyone by getting elected."

Some businessmen resent Sanders' efforts to restructure the flow of power through city government. He opposed the construction of a new highway, which had been approved at all levels of city government, and of luxury condominiums on Lake Champlain.

Sanders says that if he is reelected he will attempt such radical steps as using the city's bonding power to raise money for low-income housing and cooperative business enterprises, such as grocery stores.

And he has railed against the city's weak mayor form of government and against the limits on his power to act.

"People ask me what I'm doing that's socialistic," he says. "What can I do? Have you ever seen the city charter?"