The conventional wisdom around New London for the last few years has been that incumbent Michael Passero was a shoo-in for re-election, the inevitable result of the lopsided dominance of Democrats in city politics.

Presumably an incumbent Kermit the frog, if a Democrat, also would win hands down.

So I certainly don't have the clairvoyance to predict anything but a Kermit win come November.

But I would urge everyone to pay attention Thursday to the first debate of the three mayoral candidates, as this race has turned into, if not a close one, a fascinating engagement, maybe even a turn in city politics.  (A video of it will be on www.theday.com Friday.)

As someone still cheering most of Connecticut's Democrats in Washington, part of the bulwark against Trump, I have become increasingly leery of the party's power brokers in Connecticut government, as New London's port has been turned over to competitors from New Haven with political muscle and state elections are now supervised by a Democratic partisan who had to resign from a quasi-public agency so corrupt it was awarding contracts to friends and maxing out debit/credit cards on food and drinks.

The dynamic of Democrats counting on the underprivileged vote in New London seems to be in play this election, with the Green Party fielding a serious candidate, Frida Berrigan, who promises to turn her attention to a constituency I think Democrats here have long taken for granted.

Berrigan promises a fresh perspective on city politics. She is smart, engaging and charming. It can't hurt that she is from the famous family of peace activists, with her own long history of working with the poor.

Google and watch the video of movie star Martin Sheen, a family friend, enthusiastically embrace and endorse Berrigan, in English and Spanish, to get a glimpse of New London politics with a new twist.

Pay attention in the three-way debate to Berrigan speaking for the voiceless and demanding, pleasantly and succinctly, that big institutions that take so much from the city finally give more back. She says she can coexist with the city's largest employer, the maker of the nuclear submarines her family has so vigorously protested against.

Listen to her suggestion that the city solicit help from rich interests, like the wind companies eyeing the port, to finally build a community center for city residents. Maybe Mayor Passero will mention how his own talk of a community center ended years ago, after the City Council refused, in the face of no clear plan, to buy land from a political donor of the mayor's.

But wait. It's a three-way race.

The Republican, Martin Olsen, is doing surprisingly well in the lawn sign contest. Olsen seems to have captured the attention of a big swath of the southern end of the city, with his complaints about runaway taxes and big spending by a top-heavy Passero administration.

My favorite taunt by Olsen is when he cites all the administration executives who earn multiples of average city wages and don't live here, as required by the charter.

This rebuke always makes the mayor fume, as if violating the city charter is no longer fair game for criticism, after you've been doing it brazenly for years.

Olsen is good at picking at other Passero scabs, like the bad deal he accepted for New London's share of revenue from the rebuilt State Pier. Passero, too, complains about the city's paltry take, even though he endorsed the deal in front of television cameras when the governor came to town to present it.

More big Democrats have been taking the Passero tour in New London, with downtown appearances by Lt. Gov. Susan Bysiewicz and, this week, U.S. Sen. Chris Murphy. They both visited the Passero stage set downtown, where the city has painted over the blight, installed fake windows and rigged empty storefronts with blackout tape.

This is the downtown Passero was prepared to abandon, moving most city offices away, until the landlord for the building where City Hall was to move, historic land records and all, got arrested. Oops.

The Democratic machine has been smoking with its Passero help, including a high-octane fundraiser organized out of town by state Treasurer Shawn Wooden's political muscle and by a lobbyist with a lot of city business on his agenda.

Could it be that Democrats are worried about the unthinkable — Kermit losing?

Berrigan says she will work for the disadvantaged. Olsen appeals to the struggling. Passero has the advantaged covered.

The fun starts at 6 p.m. Thursday at the Jennings Elementary school at 50 Mercer St. Doors open at 5.

This is the opinion of David Collins.

d.collins@theday.com