“I’m last on their list,” he said.

“I think they’re trying to find their way in a new environment where grass-roots advocacy is more powerful and important than it’s ever been. The old way of doing business for them is no longer applicable in the new Senate.”

While the industry was shoring up its public image, it also took to the courts. In July, t he Rent Stabilization Association, Community Housing Improvement Program and seven building owners sued the city’s Rent Guidelines Board to block the new rent regulations as unconstitutional. The RSA hired a data research firm to make its case that the regulations have slowed construction, reducing tax revenues and jobs.

REBNY is hiring an organizer and has crunched data to warn that tax revenues from real estate sales are down. The Community Housing Improvement Program changed lobbyists and tactics.

“The lobbying strategy is different,” said Mr. Martin of CHIP. “It has to be different. This presumption that you just call up, you sit down with an elected official, you say, ‘This is what I need,’ and that’s it — that doesn’t work anymore. Everything needs a campaign behind it, it needs different voices, it needs tenants, it needs contractors who have been laid off.”

Mr. Strasburg of the Rent Stabilization Association said that Democratic lawmakers who used to work with him were now afraid to stand up against their ascendant progressive wing. “There are those that said to me, ‘I can’t take your money now, but after January 15 I can take your money.’ Why after January 15? Because it’s too late for anyone to make it an issue” in the 2020 elections, he said.

Mr. Strasburg said he refused to support lawmakers who did not stand up for the industry, even if they had in the past. One state senator who voted for the rent regulations asked for support against a primary challenge from the left, and Mr. Strasburg was flummoxed. “I said, ‘Why would we help you?’ He said, ‘Because they’re worse than I am.’ I said, ‘But at the end of the day you voted the way that they would vote. So what separates you from them in terms of bad?’”

REBNY has tried to cultivate more centrist Democrats — or at least those that haven’t sworn off real estate money — giving $84,500 to 14 Democratic state senators since the start of the year, compared to just $2,000 to Republican senators.