After years of decline, increases in American youth tobacco usage have pushed the tobacco control debate back into the forefront of the public health conversation. Youth tobacco use increased from 2011 to 2018, largely driven by e-cigarette usage, which grew from 1.5% to 20.8% of American high school students, representing an increase of 2.83 million adolescents. Despite extensive evidence that e-cigarette chemicals cause morbidity including immediate, harmful changes in endothelial function in healthy nonsmokers, 72% of teenage e-cigarettes users believe e-cigarettes cause some, little, or no harm. New evidence of harms is emerging as the CDC investigates over 450 cases of severe, unexplained respiratory symptoms after reported e-cigarette use in 33 states. Both states and regulators have taken note, with a cascade of actions in the form of state bans of flavored e-cigarette products, FDA warning letters, and FTC marketing practice investigations.