It looks like Massachusetts is set to become a new medical marijuana state. According to a new Public Policy Polling survey, the medical marijuana initiative there has the support of 58% of likely voters, while only 27% say they plan to vote against it.

The initiative, which will appear on the November ballot as Question 3, would allow people suffering from a debilitating medical condition to use medical marijuana upon the recommendation of a doctor with whom they have a bona fide relationship. Patients could possess up to a 60-day supply -- what constitutes that supply will be determined by the Department of Health. The initiative would also set up a system of nonprofit medical marijuana cultivation and distribution centers.

The initiative is being championed by the ACLU of Massachusetts, the Committee for Compassionate Medicine, and the Massachusetts Patient Advocacy Alliance.

The PPP survey found that Question 3 is winning broad support among Democrats (67%) and independents (55%), but also surprisingly high support (46%) among Republicans. Following the pattern in other states, support was stronger among men (61%) than women (55%) and stronger among people describing themselves as very liberal (77%), liberal (67%), and moderate (60%), than among those describing themselves as conservative (41%) or very conservative (37%).

Even if all the undecided voters (15%) joined those saying they will vote no, the measure would still win by 16 percentage points. Some drop-off in support is to be expected as election day nears and the opposition mobilizes, but it looks very likely that there will be at least 18 states to approve medical marijuana as of November.