Metro

Thompson a sleeper candidate, but not asleep

He’s the front-runner nobody’s talking about — so low-key that many people think he’s not even running.

But political insiders say mayoral candidate Bill Thompson, who lost to Mayor Bloomberg by a slim 5-percentage-point margin in 2009, is the only contender with a clear path to a Democratic runoff in 2013, and is widely expected to be one of the last politicians standing in the crowded race.

“The fact that he has a stealth campaign right now means nothing,” said political consultant George Arzt. “You don’t want to start a mayoral campaign publicly this early, or people will be sick of you by June. In the end, Bill Thompson is likely to be a runoff contender.”

The former city comptroller raised a paltry $500,000 over the past six months and is dead last in the cash count, with a small, $1.5 million war chest, despite declaring for the race three years ago.

But as the only black candidate, Thompson can count on between 75 and 90 percent of the African American vote, political analysts say — about 22 percent of the total primary vote. If Thompson, more socially conservative than his Democratic rivals, captures 50 percent of the Latino vote, that would put him up to 35 percent in the primary.

“The question for him right now is can he get up to 40 percent,” said a strategist.

The city requires a runoff between the top two vote-getters if no candidate in the primary, scheduled for Sept. 10, 2013, wins at least 40 percent of the vote.

Thompson, who works for municipal investment bank Siebert Brandford Shank & Co., has purposefully kept a lower profile than his rivals.

“He thinks it wouldn’t be graceful to be a shadow mayor,” said a source close to Thompson. “If he’s out there pissing on Bloomberg’s shoes too much, that’s not very mayoral.”

But just because he’s quiet doesn’t mean he’s dormant.

When he begins campaigning full time, “Bill will be at every debate, and he will spend every dollar he has on television ads to show New Yorkers that he’s black,” said a political source.

“There is no such thing as a shoo-in, but I’m happy with where I’m at,” Thompson told The Post. “I’m not concerned with what people say or write about me now. It’s more important what everyone’s saying and writing next year.”

It’s not the first time Thompson has played the role of tortoise against hares.