New Jersey voters have until 8 p.m. Tuesday to elect all 120 members of the state Legislature.
Polls opened at 6 a.m.
The off-year elections end an underwhelming campaign season where only a handful of races are competitive because newly redrawn legislative districts favor incumbents.
Democrats control the Senate 24-16 and the Assembly 47-33.
Republicans aren't expected to make major gains despite Gov. Chris Christie's popularity in the polls.
Christie says he'd consider the midterm elections a win for the GOP if the party holds the seats it now occupies.
Republicans could pick up two seats in the Senate if they upset incumbent Democrats in Bergen and Atlantic counties.
Assembly races in Burlington and Bergen counties are also seen as toss-ups.
Voters statewide will consider a sports betting question.