When Douglas Horn drove a truck into a ditch in 2012, he could not have imagined it was the first step in a series of events that would eventually land him in front of the U.S. Supreme Court.
The wreck left Horn with shoulder and hip injuries and aggravated existing issues with his back. Seeking relief, he looked to a CBD product derived from hemp that was advertised as not containing THC, the active ingredient in marijuana. As a driver, he had to submit to regular drug testing. A positive THC...