It starts in China, runs through Mexico and ends in mortuaries all across America. This is the fentanyl trail -- that, so far, our government has failed to block. In 2003, according to the National Institutes of Health, 1,400 Americans died by overdosing on what that agency calls “synthetic opioids other than methadone (primarily fentanyl).” By 2008, President George W. Bush’s last full year in…