Before Sen. Bernie Sanders announced he was entering the race, Sen. Kamala Harris was dubbed the front-runner for the Democratic presidential nomination in 2020. And she made the most of her short time in the top spot. The California senator succeeded in establishing herself as a formidable candidate after only two years as a national figure. She’s now in the top tier of candidates along with Sanders, an independent from Vermont, and former Vice President Joe Biden, assuming he decides to run. It's heady company for Harris, 54, who was district attorney of San Francisco from 2004-2011 and the California attorney general from 2011-2017, when she became a U.S. senator. Her swift rise brings to mind former President Barack Obama, who won a Senate seat in 2004 and the presidency four years later. Harris dislikes...