Biden Sweeps South on Super Tuesday, Revives Campaign in Momentous Showing

Joe Biden powered to a dominating sweep of the South and surprisingly strong showings in New England and the Upper Midwest on Tuesday night, as he sought to seize control of the Democratic presidential race and overtake Sen. Bernie Sanders as the delegate leader.

Sanders was holding on to a lead in California, the state with the biggest delegate haul of the Super Tuesday primaries, as votes were slowly counted there. But Biden’s victories in Texas and eight other states threatened to at minimum erase the lopsided delegate advantage Sanders...

Momentum and timing matter in politics — and both helped former Vice President Joe Biden mount a comeback from almost-left-for-dead to being the alternative to Vermont Sen. Bernie Sanders, who went into Super Tuesday with front-runner status after significant wins in early states.

The Democratic presidential race at one point had almost two dozen candidates, but now it's essentially a contest between two men representing dueling ideological poles of the party.

Sanders has energized the progressive wing with promises to transform the party and dramatically expand the government's role.

Biden's...