Being mayor of New York City isn't easy under the best of circumstances, but Mayor Bill de Blasio seems to be having a tough time with some of the very New Yorkers who helped him win City Hall. NY1’s Grace Rauh filed the following report.

Police reformers who celebrated de Blasio's victory now wonder what happened. There were no indictments for Eric Garner's death. The officer who put Garner in a chokehold still works for the police department.

"That's a real bad sort of wound that we're dealing with now," said Bertha Lewis, president of The Black Institute. "And it will be an issue in 2017. Absolutely."

The mayor's speech at a memorial for Garner earlier this month also rankled some. He said all lives matter: black lives matter, he said, and, referring to the police, he added that blue lives matter too.

"If you're going to make a speech at a memorial, then just talk about that black life. Don't tell me about blue lives," Lewis said.

His fight with the car service company Uber exposed vulnerabilities as well. The company's well-funded campaign won support from black lawmakers and clergy who argued that yellow taxis have long discriminated against New Yorkers of color.

The mayor's usual progressive partner, City Council Speaker Melissa Mark-Viverito, could not hide her frustration with him over Uber last week.

One-time de Blasio supporter Russell Simmons pounced earlier this month. The mogul and animal rights activist is upset that de Blasio still has not outlawed horse-drawn carriages, like he promised.

"He's got to have a lot more heart to be a good mayor," Simmons said.

Even activists largely in the mayor's corner say they plan to push City Hall.

"We actually need to be dealing with the homeless crisis. We need to be dealing with low-income housing as we know it," said Jonathan Westin of New York Communities for Change.

Despite the criticism from some members of his base, political observers NY1 spoke with say they find it difficult to imagine a situation in which de Blasio faces a serious Democratic primary challenge when he's up for re-election.