Support for Donald Trump in the 2016 presidential election was greatest in the counties with the highest rates of chronic prescription opioid use, according to a new study published this week in the journal JAMA Network Open. The study found that Trump received about 39 percent of the 2016 vote in the 638 counties with the lowest rates of long-term (90-day supply or more) Medicare opioid prescriptions, but about 60 percent of the vote in the 693 counties with the highest rates of long-term opioid use.