After months of hedging and hand-wringing, New York City mayor Bill de Blasio has finally endorsed his old boss, Hillary Clinton.

“The candidate who I believe can fundamentally address income inequality effectively, the candidate who has the right vision, the right experience, and the ability to get the job done, is Hillary Clinton,” he told MSNBC’s Morning Joe on Friday.

Clinton and de Blasio’s paths have been intertwined ever since he managed the Senate campaign that launched her political career in 2000. But the far-Left mayor, worried about Clinton’s reputation as a centrist Democrat, pointedly declined to endorse her when she first announced her presidential candidacy in April. “I want to see a vision,” he said at the time. “It’s time to see a clear, bold vision for progressives.” He had refused several invitations to endorse Clinton since then.

But with Vice President Joe Biden’s refusal to run and with almost every other major New York Democrat now behind the Clinton campaign, a de Blasio endorsement became all-but inevitable — despite the mayor’s misgivings.

#share#“I have seen her vision and platform develop over five months. I’m extremely pleased with what she’s put on the table,” de Blasio said Friday. “She has a history of fighting on issues that convinces me.”

The Clinton campaign didn’t exactly trumpet the news, lumping de Blasio into a press release on 87 mayors who recently endorsed Clinton. The release, which made no specific comment on de Blasio’s support, called the endorsements “another sign of the campaign’s growing momentum.”

#related#That momentum is real. Following on the heels of a strong debate performance and an appearance before the House Benghazi Committee that left her largely unscathed, Clinton’s poll numbers shot up in Iowa earlier this week. In two separate polls of the Hawkeye State, she was given 38- and 41-point advantages over her closest rival, Vermont senator Bernie Sanders.

De Blasio’s endorsement of Clinton is surely a blow to Sanders, whose progressive politics are more closely aligned with the mayor’s own. In announcing his endorsement of Clinton, de Blasio went out of his way to single Sanders out for praise.

“Bernie Sanders has done something very good for this country,” he said. “I think Hillary Clinton is the person to get it done best. But I want to be very clear: Bernie Sanders has moved the discussion in this country in a very productive way and I think we needed that.”

— Brendan Bordelon is a political reporter for National Review.