Good for Bill Thompson. He took an unflinching look at the unofficial returns from last week's mayoral primary, excoriated the city Board of Elections for not crunching the vote totals faster, then graciously bowed out of the Democratic race for mayor Monday.

That's welcome news for a party that enjoys a 6-to-1 edge over Republicans in the city but hasn't managed to put a Democrat in Gracie Mansion since 1989.

Thompson's withdrawal allowed the Democrats to bask in a kumbaya moment on the steps of City Hall that included Bill de Blasio, now the Democratic mayoral nominee, as well as Gov. Andrew Cuomo and Michael Mulgrew, president of the United Federation of Teachers.

The stakes in this race couldn't be starker now.

The major-party players left standing are de Blasio, the city's public advocate, who will run a populist campaign, and Republican Joe Lhota, a policy expert appointed by Cuomo in 2011 to head the MTA.

We're hoping for a vigorous and illuminating debate.

De Blasio has tapped into a progressive zeitgeist, building momentum with calls for income equality, for stronger neighborhood health care networks, and for a prekindergarten program funded by a new tax on residents making more than $500,000 a year.

Lhota is campaigning as the guy who can get things done. He steered the MTA through the Sandy crisis with competence, getting North America's largest transit system running again with remarkable speed. He has a solid private sector resume and a respectable record as a deputy mayor in the Giuliani administration.

They will be making their cases in a city that has come down with a pronounced case of Bloomberg fatigue.

As for Thompson, he has served New Yorkers well over the decades -- as city comptroller and as president of the now-defunct Board of Education. He shocked many in 2009 when he came closer than expected to derailing Michael Bloomberg's plans for a third mayoral term.

We hope his voice continues to be heard. Maybe he can spearhead a push to reform the city's Board of Elections.