Mr. Cuomo’s relationship with the I.D.C. — which formed shortly after the beginning of his first term in 2011 — has also been a potent talking point for Mr. Cuomo’s primary opponent, Cynthia Nixon, who campaigned with several of the challengers on Tuesday, rallying in Union Square in support of abortion rights. At that rally, she said that Mr. Cuomo had “prioritized supporting the I.D.C.” over passing bills to protect women’s reproductive rights. (Mr. Cuomo’s office called Ms. Nixon’s criticism “self-serving election year games.”)
Mr. Cuomo, 60, seemingly has much riding on Democratic efforts to retake the Senate, repeatedly calling it a priority in this year’s elections; Democrats are currently a single vote short of taking control of the 63-seat house.
And on Wednesday, his campaign reiterated that sentiment, while taking a swipe at past efforts to unite Democrats as well as President Trump’s “destructive, ultra-conservative agenda.”
“For over a decade the Senate Democratic Conference has been dysfunctional and fractured,” said Abbey Fashouer, a campaign spokeswoman. “The governor supports Democratic unity and is 100 percent focused on growing the Democratic majority in the Senate by picking up seats.”
In April, the governor sat at a table in his Midtown office to announce a détente in the schism between Mr. Klein and Ms. Stewart-Cousins, saying “we are uniting the Democratic Party to fight a common enemy for the greater good.”
How real that unity was, however, has been an open question for months, as some members of the mainstream Democrats have only warily welcomed the former I.D.C. members back into their conference. During its seven years in existence, one of the most outspoken critics of Mr. Klein’s group was Senator Michael Gianaris of Queens, who was supplanted by Mr. Klein as deputy minority leader.
Mr. Gianaris has said he wants nothing more than a Democratic-led Senate. But in an interview on Wednesday, he indicated that didn’t necessarily mean throwing his support behind the eight members of Mr. Klein’s old group.
“I will not be supporting,” he said, “any of the former I.D.C. members.”