The economic arguments in favor of legalizing pot are no hallucination. Forecasting firm IHS Global Insight reports that Washington state could pull down nearly $2 billion in additional revenue over five years, through fees on licenses granted to pot providers. Colorado, which would manage pot sales differently, could earn about $342 million from excise taxes over five years. In a tough economy, with voters staunchly opposed to most new taxes, that’s a meaningful amount of revenue.