BURLINGTON, VT. -- ''I'll be straightwith you,'' said the straight-arrow Vermonter, a member of the city police force for 17 years and a political conservative. ''At first, we were wary of Bernie Sanders. The socialism stuff. We didn't know what to expect. But after eight years with him, I can tell you that he's played fair. The police respect him.'' Who'd have guessed? Probably as few people who would have predicted eight years ago, when Bernard Sanders came into office with a 10-vote victory, that he would be named in 1987 by U.S. News and World Report as one of the 20 best mayors in America. In his city hall office, which has the cozy feel of a hangout, the nation's only Socialist mayor said he was emotionally and politically prepared to become in a few days the nation's only ex-Socialist mayor. He didn't seek reelection in early March. After winning four two-year terms in Vermont's largest city, and collecting more votes in the last three elections than his Republican and Democratic opponents combined, Sanders at 47 is ready to explore options. One is the usual: lecturing and writing. The other is to make a second run for Congress. Sanders lost in a squeaker in November, coming in second by 3 percentage points to a Republican while beating a Democrat two to one. "It's not easy changing the world," Sanders told supporters election night. What has been easy, at least in the world of Burlington, is changing minds about Socialist politics. In theory, and as explained in the works of Norman Thomas, Eugene Debs and Michael Harrington, democratic socialism is the radical narrowing of differences between the ideal and the real. In practice, it's Sanders in Burlington working successfully to deliver a $52 million pollution-control program to protect Lake Champlain and Burlington harbor. Or creating the Burlington community land trust, the first of its kind in Vermont or getting a law passed to require that 10 percent of city-funded trade jobs go to women. To the locals, Sanders was the workhorse who did that and more. Nationally he was seen by the protectors of the conventional as the head of ''the People's Republic of Burlington'' whose followers were ''Sandernistas,'' and isn't it a howl. ''Up here,'' says the Brooklyn-born Sanders, ''when you're the mayor for eight years and dealing with day-to-day situations, you've got to be treated seriously. For me, and for the people of Vermont, the word, quote-unquote, socialism is not a big deal. Around the rest of the country, it still has a connotation of being a freak show. I remember doing a radio program in Arizona, and it was like, 'This guy has three heads, ladies and gentlemen.' It was a circus. That's unfortunate. It indicates the lack of knowledge that our people -- our citizens -- have about what's going on around the rest of the world, even in Canada or Scandinavia, in terms of democratic socialism.'' Sanders, married and the father of a college-age son, is a gritty, exacting thinker whose admonitory words bring back to life a rich dye of radicalism now all but lost in colorless American politics. If he speaks intensely about exploitation of the poor or the knaveries of decadent capitalism, it's because he has the details of eight years in the mayor's office to draw on. During the Sanders tenure, Burlington, rising to the ideals of its mayor's populism, voted repeatedly for progressive reforms in tax laws, cable-television rates, environmental regulations and poverty programs. But when citizens rally for changes, according to Sanders, ''the business community -- the people who have the money -- go running to the courts or state legislature to overturn what we have done. There is a frustration that you can't really do what the people want.'' Sanders recites a number of reforms approved by the ballot in Burlington but later defeated at the state level judicially or legislatively. After years of that, he believes, ''Instinctively citizens understand that the game is rigged against working people and poor people." When national reporters occasionally dropped by Burlington to check up on Sanders -- does the comrade have the hammer and sickle waving over city hall? -- the one adjective sure to be used was ''avowed,'' as in ''the avowed Socialist mayor.'' No one is ever called an avowed Democrat or an avowed Republican. As used by media centrists, the term is meant to convey mock alarm -- watch out for these avowed guys, they're unpredictable and might do anything. Let it be hoped that Bernie Sanders does stay avowed. He leaves office scorned by some of Burlington's rich and blessed by most of its poor. If he takes a vow of obedience to that high standard, he has decades to keep on keeping the faith.