NEW YORK — To anyone who figured the path of legalizing recreational marijuana use ran along blue state-red state lines, a sudden setback for pot advocates in New Jersey may show the issue isn’t so black-and-white.

Leaders in solidly-blue New Jersey are vowing it will still become the 11th state to legalize the drug. But when a state Senate vote was abruptly put off Monday because it didn’t have enough support, the delay was a reminder that the politics of pot legalization aren’t purely partisan. The key question instead can be whether voters or legislators are making the decision, experts say.

“It’s a good illustration that even in a state that’s entirely Democratically controlled, it’s not obvious that it would be passed — or that it would be easy,” says Daniel Mallinson, a Penn State Harrisburg professor who studies how marijuana legalization and other policies spread among states.

Since voters in the states of Colorado and Washington decided in 2012 to let adults use marijuana for fun, legalization has traveled a route that looks — from a distance — something like the red-and-blue maps that frame many a U.S. political conversation.

Residents of Democratic states on the West Coast and parts of the Northeast, for instance, have said yes, as has the District of Columbia. Lawmakers in Republican-led North Dakota and Arizona have said no.

But look closer, and the trend isn’t so clear. Voters in Ruby-red Alaska OK’d recreational pot in 2014, while legalization fizzled this year in the state legislature in deeply Democratic Hawaii .