In the wake of the first round of debates in the 2020 Democratic presidential primary, former Vice President Joe Biden has taken a serious hit, while Sen.s Kamala Harris (D-Calif.) and Elizabeth Warren (D-Mass.) are on the ascendant, along with Pete Buttigieg, mayor of South Bend, Ind. Sen. Bernie Sanders (I-Vt.), the 2016 runner-up, has fallen behind. Even so, both Sanders and Biden are maintaining a strong presence in the race. The race seems to be shaping up as a battle between these five candidates.While the first votes in the Democratic primary will not come until next year, it...