A recent WBUR poll suggests Massachusetts is leaning toward voting to legalize recreational marijuana on Election Day. All of the polls in recent months have shown the “Yes” side on Question 4 leading by a margin of 5 to 15 points.

In favoring legalization, Massachusetts voters are following a national shift in public opinion on marijuana.

A recent Pew Research Center poll shows the share of Americans who favor legalization is reaching an all-time high of 57 percent. Young voters tend to be even more in favor of it, both here and nationally, suggesting the shift in the polls on marijuana may continue.

Most Massachusetts polls show residents are in favor of marijuana legalization.

But before supporters fire up the celebration, a few notes of caution. Because there are no big Massachusetts seats up for grabs this election, there have been just four polls since May that covered the Massachusetts ballot questions. In 2014, which featured a competitive governor’s race, U.S. Senate race and other statewide offices, there were roughly 10 times as many polls over the same period.

Even with more polling, ballot questions can be tricky to forecast. Ballot questions are often lengthy and complex and they lack easy partisan cues to help voters decide how to cast their ballots. Voters also often tune in late, just as ballot campaign advertising floods the airwaves. Pollsters missed the mark on the 2014 ballot question on gas tax indexing.

If the polls are wrong and Question 4 burns out, it won’t be because voters think marijuana is immoral or personally dangerous. Half of voters in the latest WBUR poll say they've tried marijuana themselves, and a large majority are OK with others using marijuana in their own homes. Instead, concerns about seeing marijuana in public and perceived public health risks are holding some voters back.

Still, if history is a guide, legalization appears likely to pass. There have been many non-binding referenda on legalization at the local level. These non-binding votes have done a pretty good job predicting the winning margin when the binding question gets to the ballot.

We'll have to find out on Nov. 8 if that same pattern holds true.