Lt. Gov. Gavin Newsom, joined by leaders in law enforcement, public health and social justice, announced Wednesday in San Francisco that enough signatures had been collected to put recreational pot up for a vote in this year’s presidential election. The broad array of marijuana proponents, marking the official launch of their statewide campaign, overcame the hurdles of competing priorities and scant funding, on top of general unease about the drug. The common refrain among those at the Commonwealth Club on Wednesday afternoon was that the nation’s war on drugs was failing children and impoverished communities. The pending ballot measure calls for the state to regulate marijuana under a set of rules that includes a 15 percent tax on retail sales and penalties of up to $100 for illegal possession. [...] six years later, with four states having legalized recreational pot and public support growing for decriminalization, the new coalition said the Adult Use of Marijuana Act stood a good chance of succeeding. Campaign officials said they submitted more than 600,000 signatures to the secretary of state’s office, far more than the 365,000 needed before the June 5 deadline.