In New Jersey, the northern suburbs have traditionally been Republican, and are key bases of support for Representatives Rodney Frelinghuysen and Leonard Lance. With Philip D. Murphy’s victory in the race for governor on Tuesday, however, that support began to fracture: Mr. Murphy outperformed expectations in the region, Republican incumbents were ousted and candidates in otherwise fairly safe districts had some of the closest elections of their careers.

And in Albany, the election results heightened pressure to dismantle the Independent Democratic Conference, the coalition of rogue Democrats who have partnered with Senate Republicans to help give them control of that chamber, despite the Democrats’ numerical majority. But, one perennial question remained: How much capital would Gov. Andrew M. Cuomo and Mayor Bill de Blasio of New York City invest in those efforts?

Mr. Cuomo has long talked of the need for unity among Democrats in the state Capitol, but has also had a history of working with Republicans and the Independent Democratic Conference. Mr. de Blasio has been more overt about trying to elect fellow Democrats in Albany: In 2014, he actively maneuvered to unseat Senate Republicans, though his initiative backfired when his fund-raising efforts to aid Democrats in those races led to federal and state investigations.

On Wednesday, the governor seemed more focused on Republicans in Congress than state lawmakers. “I think you’re going to see an even greater turnout against what the Republicans are doing next year by Democrats and Republicans and Independents,” he predicted. “It’s going to be a very good year. Any of these Republican congressmen are in very deep trouble.”

Back in New York City, the mayor added his own rosy forecast at a postelection news conference at City Hall. “If you have the Democratic Party in charge of the Assembly and the Senate, governorship, county executives, mayor of New York City, City Council of New York City,” he said, “you’re going to have a more progressive city and state.”