"There is not a better candidate for county executive than Tom Suozzi," Jacobs said. "So, my goal is to get him to change his mind."
Suozzi, who served two terms before losing a tight race to Mangano in 2009, said his mind is made up. "I am not running," he said Thursday. "I am really enjoying my time with my family and my career."
Ten months before the election, the Democratic field remains unsettled.
The list of potential candidates includes Roslyn school board member Adam Haber, who has publicly declared his candidacy, North Hempstead Town Supervisor Jon Kaiman and Legis. David Denenberg of Merrick.
"I am someone who is committed, who cares and who can make a difference," said Haber, an East Hills resident who previously worked in finance and commercial real estate.
Denenberg said he is "seriously considering" a run against Mangano but also would consider challenging GOP Comptroller George Maragos.
"My priority is to serve the county in whichever way I can do the most good," he said.
Kaiman's office did not return calls for comment.
Jacobs had flirted with a run for county executive if he could not persuade Rice or Suozzi to enter the race. But Jacobs said he is now comfortable with the potential field of candidates. "Barring something extraordinary, it will not be me," he said.
Democrats expect to choose their nominee by the end of the month, Jacobs said. Mangano spokesman Brian Nevin said "residents know that Ed Mangano froze property taxes for three straight years and cut wasteful spending by hundreds of millions of dollars. That's something voters will surely remember in November."