In New York’s search for a mayor to succeed Michael Bloomberg, you’d think Bill de Blasio would loom large, and not just because he’s 6-foot-5. He is policy-smart, progressive, politically savvy and untouched by scandal. He’s connected. (He ran Hillary Clinton’s first Senate campaign.) He holds a citywide job, public advocate, that, while not very demanding, is nominally next in line to the mayor. From that post he has been none-too-subtly campaigning for the top job since 2010. As the city emerges from 20 years of Republican and independent leadership and shows its true colors — which are, by most indications, deep blue — candidates don’t come much bluer than Bill de Blasio.

Until last week, though, de Blasio’s poll numbers were stalled in the low teens. Even after Anthony Weiner joined the walking dead and de Blasio’s numbers blipped upward, he tended to be a subordinate clause in the news coverage. When I asked various New York political sages why his campaign wasn’t getting more traction, I heard two answers. One is: “wrong narrative.” In an electorate that is ready for some change, the critics theorized, de Blasio was offering too much change. The other was: “no base.” The contenders include a woman who is proudly gay (Christine Quinn, the City Council speaker and front-runner), an African-American who has started waving the Trayvon Martin flag (Bill Thompson, who came within five points of Bloomberg in 2009) and a Taiwanese-American immigrant (John Liu, the city comptroller) who claims to have a lock on Asian New York. In that company, some suggested, a white guy, even a white guy whose wife of almost 20 years is African-American, is at a disadvantage. And, although he comes from Brooklyn and has an Italian surname, he is too liberal to be the standard-bearer of the outer-borough white ethnics.

The “no base” argument is probably too glib. Identity politics still plays its part in New York, but it is not so obvious or so predictable. New York’s minorities — and the city is nothing but minorities — are hardly monoliths. De Blasio has the endorsement of a union, the health care workers of 1199, with a large black membership and a potent vote-wrangling reputation. Black neighborhoods went strongly for Thompson in the 2009 mayor’s race, but they also went strongly for de Blasio as public advocate. In any case, it’s too early to read much into polls. As recently as last week the Quinnipiac survey showed the leading candidate among black voters was still Anthony Weiner.

But the sages are onto something when they suggest that the election, and de Blasio’s campaign in particular, is a test of the city’s appetite for change. It is in a sense a referendum on the Bloomberg years.