Last year, that task proved daunting for the mayor. This year was different.

Mr. de Blasio arrived on time — a few minutes early, even — to the service in Queens, taking a small step toward repairing his reputation for tardiness among attendees still angry about his late appearance a year ago.

[. . .]

Geri Prado, executive director of the Progressive Agenda Committee, said in a statement on Tuesday that the forum had become unnecessary, because inequality had already moved to the center of the campaign conversation.

The committee had circulated invitations to leading Democratic and Republican presidential candidates, asking them to participate in a public event at the University of Iowa on Dec. 6. The deadline for candidates to respond to the invitation was to be Thursday, according to a copy of the invitation.

As of Tuesday, the University of Iowa had not received notification that any candidate had accepted the invitation, Jeneane Beck, a university spokeswoman, said.

[. . .]

The cancellation was met with expressions of relief by some members of Mr. de Blasio’s inner circle, which was deeply divided over whether the mayor should continue pursuing a forum that many had come to view as a folly.

The 2015 period coincides with Mr. de Blasio’s work in Albany with the Real Estate Board of New York, an industry group, to get state lawmakers to renew — with some changes — a city subsidy for developers known as 421-a.

Over the same months, the Campaign for One New York spent about $700,000 on political consultants, national travel and research as the mayor worked to bolster his progressive agenda — and profile.

[. . .]

The mayor’s advisers said people are giving to the group because they support Mr. de Blasio’s positions on issues like affordable housing and prekindergarten. They emphasized the group is limited to issues advocacy and can’t directly support a re-election bid by Mr. de Blasio.

[. . .]

Since its inception on Dec. 12, 2013, the operation known as Campaign for One New York has accepted $3.87 million from dozens of real estate developers, unions and others who do business with City Hall. The setup allows the mayor to raise money outside the regulations of the city Campaign Finance Board.

The contributors to his group include individuals and firms seeking approvals for their projects, and they often donate through limited liability companies that obscure their identities.

In some cases, donors gave money right before or after getting a city-granted benefit, according to a POLITICO New York review of $1.71 million in individual contributions that poured in during the first six months of 2015.

[. . .]

In March, District Council 37, the city’s largest municipal union, donated $20,000 to the campaign. Around that time, the union’s leadership was successfully negotiating raises for its lowest-paid members with the city Office of Labor Relations.

“DC 37’s support for the Campaign for One New York’s efforts to draw attention and find solutions to the city’s affordable housing crisis is based solely on merit,” DC 37 executive director Henry Garrido said in a statement to POLITICO New York.