A campaign to legalize marijuana in Ohio took a step closer to making November’s ballot Tuesday, after its promoters turned in more than twice the required number of signatures. But the measure will face competition at the polls. Ohio legislators also approved their own ballot measure on Tuesday to undermine the pot plan, which lawmakers worried would amount to a “marijuana monopoly” because of its provision that only 10 growers would control the wholesale pot market. The lawmakers’ measure would block other measures that benefit select economic interest groups. The marijuana ballot measure campaign, dubbed Responsible Ohio, is just one of many ballot measures in recent history that are designed to benefit their backers.