DETROIT —Former vice president Joe Biden, the front-runner in the race for the Democratic presidential nomination, faced down a barrage of criticism Wednesday night as his opponents sought to cast him as a relic of a bygone era, ill-equipped to lead his party as it grapples with urgent questions about race, immigration, and the best way to beat President Trump.
One by one they dug in, denigrating Biden’s health care plan, criminal justice record, support for free trade policies, and the immigration policies pursued by President Barack Obama.