More than 20,000 protestors from around 160 organizations will swarm the National Mall Sunday in hopes of intensifying the pressure on President Obama over climate policy. The president has not yet detailed the specifics of how he will address the issue, aside from a pledge made in the State of the Union address to take executive action on climate if Congress fails to make progress. Demonstrators are likely to offer plenty of loud suggestions in what green groups are branding the largest ever United States climate rally. “We’re really past the point of playing games with any of this stuff,”...