New York mayoral candidate Joe Lhota (R) Chip Somodevilla /Getty Images The next mayor of New York, if he or she is to do a good job, will have to say “no” a lot.

“No” to public employee unions who want a retroactive raise the city can’t afford. “No” to city councilmembers who will try to spend every tax dollar that comes in instead of rebuilding the city’s reserve funds. “No” to NIMBYs who don’t want anything new built in their neighborhoods. “No” to commuters seeking relief from fare increases, bridge tolls, parking fines, and an alleged “war on cars.”

Today, Dan Amira gave the candidates a “no” test, and only Republican Joe Lhota passed it. The question was: Would you shut down two subway lines for 90 minutes to save a couple of kittens who are loose on the tracks, as NYC Transit did yesterday?

Christine Quinn said she would. Bill Thompson said he would “work” to save the kittens. Anthony Weiner said he wouldn’t just shut down the subway, he’d personally crawl across the third rail to rescue them. John Catsimatidis submitted a few noncommittal lines of poetry.

It’s a microcosm of this whole campaign, in which the candidates run around making big promises with no apparent acknowledgment of the city’s tight finances, or of the fact that policy choices involve trade-offs, or even of the mayor's lack of control over certain policy areas, like income taxation, rent control, and anything the MTA does. Yes, the candidates say, I’ll save the kitties, I'll make the Wall Street fat cats pay for it, and I’ll give you a middle-class tax cut while I do it.

Only Lhota gave the correct answer: No, you do not strand thousands of New Yorkers for 90 minutes in a futile effort to herd two cats whose lives we are inexplicably prioritizing over the rats who are run over, or drowned, or exterminated in the subways every day.

The most terrifying aspect of this campaign is that New York is poised to elect its first non-asshole mayor since Abe Beame. There’s a reason big cities elect mayors like Mike Bloomberg and Rudy Giuliani and Rahm Emanuel and Richard Daley and Ed Rendell. The mayor’s main job is to say “no.” Those guys are good at saying “no.” Lhota is the only person in the field who resembles them.