During Tuesday night’s debate, Biden insisted he was in charge of the Democratic Party, but his evasions tell a different story. In an exchange about health care during Tuesday night’s presidential debate, former Vice President Joe Biden declared, “I am the Democratic Party!” He was responding to President Trump’s claim that Democrats want “socialist medicine,” a Trumpian but mostly accurate characterization of where most Democrats are on health care. Biden vehemently denied it, saying he’s not for getting rid of private health insurance.But beyond the question of health care, Biden’s claim of ownership over the Democratic Party stood out Tuesday...