A tremendous choice faces voters going to the polls in Cambridge today, with 28 people who represent a wide variety of interests vying for nine seats on the City Council.

Are they opposed to Proposition 1-2-3? Are they endorsed by the good-government Cambridge Civic Association? Did they speak in my dining hall?

But no matter how different those 28 potential councillors seem, they're all Democrats. Like it or not, this is a one-party town. Republicans in Massachusetts-particularly at Harvard--don't get much respect, and neither do their candidates.

And I like it. Because I'm a Democrat.

But when I go home for the summer, I am transplated from this land of Democratic pipe dreams to a town where I am part of a voiceless minority.

Nassau County on Long Island is to Republicans what New York City is to Democrats--a good old boy, down and dirty, no apologies political machine. It is one of the last great political machines in America, living and breathing not in the trenches of urban politics but in the unlikely netherland of the Long Island suburbs.

CLOSE to nothing can stop Nassau County Republicans. Several years ago Nassau's own Boss Tweed, Joseph Margiotta, was convicted and sent to jail. It didn't stop the Republicans. A federal judge recently found that, for years, the party had been forcing government workers to "kickback" 1 percent of their wages to the party. The Republicans have to pay damages, but that hasn't stopped them from completely dominating local government.

This summer, Newsday, Long Island's bible of local politics, ran a cover story outlining the several dozen men (no women) who run Nassau County, listing their outrageous salaries (mostly for part-time jobs) and their potential conflicts of interest. The Republicans will still win again this year.

Of course, you can't blame all this on the Republican party. It's the voters of Nassau County who keep returning the party to office--and on some counts, with good reason.

In general, the quality of life is good, the crime rate is relatively low, and the corruption is not the type that hurts people in an obvious way. It takes a subtler eye to perceive the conflicts of interest, arrogance and non responsiveness that plague the current Republican regime.

Demographically, the reason we Democrats lose is easily explicable. Most Democrats are wealthy commuters who care more about New York City's mayoral race than about who's fixing their streets. The only people who come out to vote are the "townies," local merchants and government workers who depend on local patronage for their livelihood.

The local government blatantly caters to these voters. Town meetings are held on Tuesdays at 10 a.m., when only people who work locally (read Republicans) can attend. Commuters are not going to take a day off of work to keep track of local government.

The continuous re-election of Republicans is usually attributable to a combination of Republican political skill and Democratic ineptitude. Two years ago, the Democrats blew a chance to win the race for town supervisor when incumbent Republican John Kiernan vowed to put a resource recovery plant in a location that was potentially hazardous to the population and the environment. Public opinion in the many areas surrounding the site was viciously anti-Republican.

The Democrat, Ben Zwirn, ran on an anti-incinerator slate and overwhelmingly won the "incinerator district." But he failed to direct any efforts anywhere else in the town. He lost miserably. As usual.

Last summer, I worked full-time as a campaign coordinator for a rag-tag bunch of Democrats, led by Zwirn, who are challenging the Republican leadership in my town, the town of North Hempstead. Having been involved in local Democratic politics for many years, I had become accustomed to the casual nature with which we all treated the futility of our efforts. But this summer, that futility hit home.