Addressing dozens of elected officials, party leaders, and others, Sweeney said the party had effectively challenged Christie on several fronts even as the governor blocked much of its agenda.
Citing successful efforts to increase the minimum wage and offer in-state tuition to undocumented immigrants, Sweeney said, "We Democrats are united behind the basic principle that everyone deserves economic and social equality, without exception."
He criticized Christie for conditionally vetoing his proposed Hurricane Sandy "Bill of Rights" legislation, which the senator said would provide greater transparency for victims of the storm who are still waiting for government assistance. Christie has said parts of the bill would impose an administrative burden and break federal law.
Sweeney also renewed a push to raise taxes on millionaires, which he said could help plug the state's $807 million revenue shortfall, and for paid sick leave. Christie has repeatedly vetoed the tax plan.
The governor said this week that imposing such a tax could cause high-income earners to leave the state, and make the state less competitive.
"We're going to return this state to a progressive, focused, caring-about-people state instead of caring about millionaires and corporations," Sweeney said.
He also criticized the governor for trying to reshape the state Supreme Court in a conservative image.
Christie has declined to renominate two justices to the court during his tenure and has threatened to do the same to Chief Justice Stuart Rabner, a Democrat. The governor has denounced the court as too liberal.
"That fight will continue until we ensure this court is made up and looks like the great state of New Jersey, not one individual," Sweeney said.
Christie spokesman Kevin Roberts said in an e-mail: "A partisan speech that skates on factually thin ice in front of a partisan audience? Not that surprising. We look forward to continuing our bipartisan work together to keep getting things done for the people of New Jersey."
Creating distance from Christie could be key but tricky for Sweeney as he eyes a gubernatorial bid. Early in Christie's first term, they worked together to change the state's broken pension and health benefits system, angering unions.
Jersey City Mayor Steven Fulop, of the party's more liberal wing, has emerged as another possible contender for the Democratic nomination. Fulop and Sweeney have sparred publicly over that city's pension system.
Senate Majority Leader Loretta Weinberg (D., Bergen), one of the party's most outspoken liberals, praised Sweeney at the luncheon as a "champion for working people throughout New Jersey."
"We would not have had paid family leave if it were not for Steve Sweeney. We wouldn't have had a minimum-wage increase if it were not for Steve Sweeney and Democrats in the Legislature," Weinberg said. "We wouldn't have a Dream Act if it were not for Steve Sweeney," referring to the in-state tuition bill.
Christie supported a phased-in minimum wage hike, but opposed annual cost-of-living increases; voters approved the measure through a referendum last year. Christie signed the tuition bill into law.
The conference in Atlantic City came as recent elections have shaken some of the party establishment. The attendees included Ras Baraka, the newly elected mayor of Newark, who was supported by Fulop and opposed by North Jersey power brokers.
For his part, Baraka said Friday: "We need a party that has principles, that has values, that represents us when we're down and when we're up."