On February 9, 2016 — the last Tuesday of Scalia's life — the Supreme Court handed down an unexpected order announcing a stay of the Environmental Protection Agency's carbon emissions rules for many power plants. The vote was 5-4, along party lines, with Scalia joining his fellow conservatives in the majority.
The environmental regulations blocked by this order were commonly known as the Clean Power Plan, and they were the Obama administration's most ambitious effort to fight climate change. Had the Clean Power Plan taken effect, the EPA predicted that by 2030 it would have reduced overall carbon dioxide emissions from utility power plants 32 percent from where they were in 2005.
But the Clean Power Plan never took effect. Though the Supreme Court's order halting the plan was temporary, Donald Trump's 2016 victory all but ensured that it would not be revived. Even if the Trump administration hadn't replaced this Obama-era policy with a significantly weaker rule, the appointment of Neil Gorsuch to fill Scalia's vacant seat signaled the Supreme Court would be highly likely to strike down the Clean Power Plan permanently if given the chance.
The problem for Democrats is that the legal defeat of the Clean Power Plan is likely not a one-off. This fight over the federal government's power to address a slow-moving catastrophe is just one battle in a multi-front war over federal agencies' power to regulate. As Stephen Bannon, then the White House's chief strategist, told the Conservative Political Action Conference a month after Trump took office, one of the Trump administration's primary goals would be "deconstruction of the administrative state."