TROY — The Democrats and Republicans in this town better watch out, because the Green Party is coming for them this fall.

The Green's nominee for city council president, you see, is a well-known Troy politician with a solid following and a long history in government. She is really going to give those corporatist Republicrats the old heave-ho.

Her name?

Carmella Mantello.

What's that? You say Mantello is a Republican?

Let's see ... Yes, a quick Google check shows you're correct about that. A little more digging reveals that the moderately conservative Mantello disagrees with the quite liberal Greens on most things under the sun, which, by the way, is a wonderful source of renewable energy. (Figured the Greens would appreciate my mentioning that.)

The ideological division has been especially obvious in recent days, when Troy's political world has been consumed by whether the city should become a sanctuary city. Mantello is among the vocal opponents of the move, while the Greens are all for it.

And yet, Mantello will represent the Greens on the November ballot. That makes sense, how?

It doesn't. It is also a source of frustration for the Greens, who, unlike the phony-baloney Independence Party and other minor parties, don't endorse major party candidates — meaning they've tried to have actual Greens represent them on the ballot. Imagine that.

But in Troy, the Greens say Mantello and other Troy Republicans have stolen their hard-earned ballot line. Again.

The game went like this: Since the Greens didn't have a council president candidate, Mantello and her supporters were able, by gathering signatures from registered Green Party members, to essentially force a write-in primary, which Mantello subsequently won.

Here's the real sneaky part: Many of the supposed Greens who voted for Mantello in the closed primary may be Republicans in emerald clothing. They register as Greens because they're in on the game.

"We estimate that about 30 percent of registered Greens in Troy are actually Republicans," said Kaleb Winters, chair of the Green Party's upper Hudson chapter.

But what's in this for Mantello? Why would the registered Republican want to represent a party with which she largely disagrees?

The answer: Doing so may help her win. It's likely that come November, a few not-well-informed voters will cast a ballot for Mantello believing she agrees with Green Party causes. They will be duped, in other words.

Consider the election for council president two years ago, when Mantello received 130 votes on the Green Party line. She ended up winning the election by 43 votes, meaning she'd have lost (presumably) without those Green votes.

Duplicity worked! Surprise, surprise.

In fairness to Mantello, the "Opportunity to Ballot" game has been common in Troy and across New York, and is employed by Republicans and Democrats alike. (While Troy Democrats declined to OTB this year, one Democrat, Rodney Wiltshire, took the Green line in the mayor's race.)

And sure, some of the blame rests with Greens themselves. If their party were stronger, after all, it would not be so easy for the Republicrats to snatch their ballot lines. It's as if the major parties are stealing candy from a wobbling toddler.

The flip side, though, is that the OTB game makes it harder for the Greens to gain a foothold, because it dilutes their message and confuses voters. That's frustrating for the party, certainly, but it should also frustrate all of us who'd like to see the major parties challenged more often by fresh voices from across the ideological spectrum.

When I talked to Mantello about all this, she stressed that she tries for any ballot line that's there for the taking — as evidenced by her also representing the Conservative, Independence and, of course, Republican parties in the fall. Mantello said she speaks for Troy voters of all stripes.

"It's not a matter of agreeing with all their principles," she said. "I represent everyone, and I'm honored that Green Party members filled my name in to represent their party."

But are they really Greens? Aren't some actually Republicans disguised as Greens?

"Honestly, I don't know," Mantello said. "If somebody does that, it's completely up to that individual."

Listen, I understand that politics isn't hopscotch, especially in Troy, and that a candidate who worries too much about namby-pamby things like "ethics" and "fair play" may soon find herself watching from the sidelines.

Still, candidates should be clear about who they are and what they believe. They can be moderate or independent, certainly, but I don't know how someone can be conservative and liberal, right and left. A candidate who claims to represent the Green and Conservative parties is not being straight with voters who align with either.

Or with the rest of us.

cchurchill@timesunion.com ■ 518-454-5442 ■ @chris_churchill