Bill de Blasio (Eduardo Munoz/Reuters)
Bill de Blasio (Eduardo Munoz/Reuters)

A New York political type made a bold prediction about the New York City Democratic primary Tuesday night. If there is a runoff election because none of the six candidates reaches 40 percent of the vote, the two top finishers will be Public Advocate Bill de Blasio and former city comptroller Bill Thompson. City Council Speaker Christine Quinn? Electoral roadkill.

My jaw dropped at the prediction since Quinn long has been the front-runner in the Democratic field. Well, she was until de Blasio started spiking in the polls. When the Aug. 13 Quinnipiac poll showed him beating Quinn, I figured he was a one-poll wonder. A few days later, the Wall Street Journal-NBC4NY-Marist poll showed de Blasio in a tie with Quinn. The latest Quinnipiac poll (Q poll) released Wednesday solidifies de Blasio’s standing as the front-runner for the Democratic nomination.

At 36 percent support, De Blasio is four points shy of winning the nomination outright. Quinn gets 21 percent and Thompson snags 20 percent. De Blasio trounces Quinn (59 percent to 30 percent) in a runoff. The competition is a bit stiffer with Thompson, but de Blasio still beats him, 52 percent to 36 percent. Quinn doesn’t stand a chance against Thompson in a runoff (57 percent to 33 percent).

Christine Quinn (Spencer Platt/Getty Images)
Christine Quinn (Spencer Platt/Getty Images)

The Q poll trend lines are not good for Quinn. Her support has remained basically flat since July 24, when her support stood at 22 percent. The trend line isn’t good for Thompson, either. He’s basically been stuck at 20 percent since July 24. De Blasio has seen a steady rise in his support from 15 percent then to 36 percent now. Another troubling number for Quinn is the “definitely not vote for” percentage. While 6 percent said there was no way they’d vote for de Blasio and Thompson, 29 percent said the same for Quinn. Kinda tough to win the nomination when you are dead to nearly a third of the likely Democratic vote.

The black vote is going to be crucial to a de Blasio or Thompson win. When I asked another New York Democratic operative last week if de Blasio, whose wife is African American, could snatch the black vote from Thompson, who is the only African American in the race, he said, “Yup … particularly amongst black women.” According to the Q poll, de Blasio beats Thompson for the black vote, 34 percent to 25 percent. In a race in which every vote will literally count, here’s another worrisome sign for Thompson. Five percent of likely African American voters told Quinnipiac that they wouldn’t vote for Thompson “under any circumstances.” Just 2 percent said the same of de Blasio.

“The political cliches, that the most liberal candidate wins the Democratic primary in New York, seems to be alive and well,” Maurice Carroll, director of the Quinnipiac University Polling Institute said in the press release. “New ideas, like his tax-the-rich proposal, win big for de Blasio. Voters seem to be getting bored with Mayor Michael Bloomberg. Almost two-thirds want a new direction by the next mayor.”

Carroll’s statement should be a warning flag for de Blasio. The most liberal Democrat does win the primary — and then goes down in defeat in the general election. That’s what happened to Ruth Messinger (1997), Mark Green (2001), Fernando Ferrer (2005) and Thompson (2009). And while voters “seem to be getting bored” with Bloomberg, those are likely Democratic voters polled by Quinnipiac.

Bill Thompson (Bebeto Matthews/AP)
Bill Thompson (Bebeto Matthews/Associated Press)

The Democratic operative who made the bold prediction of the de Blasio-Thompson runoff made another: A de Blasio nomination creates a path to victory for presumed Republican nominee Joe Lhota.

As Carroll said, the most liberal Democrat wins the New York City mayoral nomination. But in a city nervous about the post-Bloomberg era, giving a serious look at a Republican who was the budget director and deputy mayor under Mayor Rudy Giuliani and was the chief of the Metropolitan Transportation Authority might not seem like a bad idea.

Of course, Democrats could forestall all of this by voting for the more centrist Thompson, said the prognosticator — a Thompson supporter.

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Jonathan Capehart is a member of the Post editorial board and writes about politics and social issues for the PostPartisan blog.