evidence: After introducing a New Hampshire father whose 20-year-old daughter died eight years ago from a fentanyl overdose, Biden laid out a grim statistic: "Fentanyl is killing more than 70,000 Americans a year." [...] Fentanyl and related synthetic opioids are potent and can be transported in small amounts. When they first began having a major impact in the U.S. about a decade ago, they were largely being produced in labs in China and shipped into the country. [...] Some who overdose on fentanyl don’t know they’re using it. But in other cases, drug users seek it out specifically.