A measure on the November ballot will ask San Pablo voters if they support a tax on marijuana businesses. If it passes, Measure M would prompt local lawmakers to begin the process of permitting cannabis businesses, which are currently illegal. Several neighboring cities, including Richmond and El Cerrito, have passed similar measures and adopted ordinances allowing cannabis businesses. If Measure M passes, it will amend San Pablo’s business license tax ordinance to include an additional tax of up to 7%…