A monthslong effort to legalize marijuana in New Jersey collapsed on Monday after Democrats were unable to muster enough support for the measure, derailing a central campaign pledge by Gov. Philip D. Murphy and leaving the future of the legalization movement in doubt.
The failure in the Legislature marks one of the biggest setbacks for Mr. Murphy, who, despite having full Democratic control in the State Senate and Assembly, has faced constant party infighting and has struggled to convince lawmakers of his progressive agenda.