"This will create a grass-roots movement," said the former mayor , in an interview with The New York Post. "This is the kind of issue that, in many ways, is somewhat beyond politics."
Giuliani, who unsuccessfully sought the GOP presidential nomination last year and is said to be eying a run for governor in 2010, said he's committed to the traditional definition of marriage.
"Marriage, I believe, both traditionally and legally, has always been between a man and a woman and should remain between a man and woman," the thrice-married Giuliani told The Post.
Rudy's gay-marriage opposition did not stop him from moving in with a gay couple after his public split with second wife Donna Hanover. The former mayor stayed with Howard Koeppel and Mark Hsaio, who plan on getting married in Connecticut next month.
Giuliani believes Paterson's gay-marriage push is a desperate effort to garner support from fellow Democrats to make up for abysmal poll numbers.
"I think he's worried and, given his [low polling] numbers, it wouldn't be normal if he wasn't worried about a primary challenge from, I guess, Cuomo," Giuliani said. "But somebody else could also come out of anywhere with numbers like that."
Paterson introduced the gay-marriage legislation last week despite concerns from fellow Democrats that the bill doesn't appear to have enough backing to pass in the Senate.
Mayor Michael Bloomberg, who stood by Paterson’s side during the gay-marriage bill announcement, is hoping his support of the legislation will further his own political agenda. Bloomberg plans to "influence" Senate Republicans to back the bill, sources told The New York Daily News.
The billionaire mayor hopes to land support for his re-election bid from Empire State Pride Agenda (ESPA), the state's largest gay-rights group.
The ESPA will not be won over easily and has said it won't endorse a mayoral candidate until after Albany's legislative session is over. The ESPA endorsed Bloomberg's opponent Fernando Ferrer in the 2005 mayoral race.