Can Joe Biden hold the Democrats together?

Tackling the interwoven crises in the US calls for a grand bargain between his party's left and centre. The renowned author and political commentator, Ruy Teixeira, shares his thoughts in The Wall Street Journal, on why he considers Joe Biden's ultimate challenge lies in how he handles the different demographics of his party, arguing that "a successful Democratic coalition cannot rely just on the votes of the party's rising constituencies; it also needs serious backing from non-college-educated whites and other less supportive voter groups."