The field is especially crowded in Queens, where well-known Democrats will also be jockeying for backing from the influential county party.
But even if they don't get that endorsement, many of them are vowing not to go away quietly.
It could be a new test for the Queens Democratic Party, viewed as the strongest and most cohesive of all the boroughs. The party still wields considerable power, but has a spotty endorsement record - especially when it comes to citywide races.
"County support is significant. They bring expertise and organization with them," said Councilman Peter Vallone Jr., who is eying a run for borough president. "I hope to have county support but should I decide to run, I'm prepared to run without it."
Vallone said 2009 will be unlike other election years.
"There will be well-known and qualified candidates for every open office who will also be able to band together," he said.
But Michael Reich, executive secretary of the Queens Democratic Party, said he isn't worried about insurgent candidates banding together in a primary.
An endorsement from the party can be a "significant advantage," Reich said. This is especially true for collecting signatures and fund-raising. But it's not "make or break," he conceded.
For example, Queens Democratic leaders backed two losing candidates in the last two mayoral primaries: Alan Hevesi in 2001 and Gifford Miller in 2005.
More recently, it backed Elizabeth Crowley in a special election for the 30th Council District. Crowley narrowly lost the nonpartisan race to Republican Anthony Como.
But state Sen. John Sabini, a longtime party loyalist who was facing his first primary without support from the Democratic party, decided not to chance it. Gov. Paterson has appointed him to head the state Racing and Wagering Board, saving him from a bruising primary against Councilman Hiram Monserrate.
"They are not omnipotent but they are still potent," said Doug Muzzio, a political science professor at Baruch College. "They have the troops and the wherewithal to make life miserable for a challenger."
The Queens party was key in selecting the past three Council speakers. Even though the last two - Gifford Miller and Christine Quinn - were from Manhattan, the party scored by getting key committee appointments for the Queens delegation.
And Muzzio said the party may be more interested in the most local races of all - the district leaders and judges.
"The key element is the selection of judges," Muzzio said. "That is the last great bastion of political patronage."
