Rep. Alexandria Ocasio-Cortez of New York and Sen. Bernie Sanders of Vermont - champions of the left - repeatedly targeted President Donald Trump and his billionaire ally Elon Musk as they kicked off a three-day swing through three electorally important western states. But Sanders, and especially Ocasio-Cortez, also trained some of their fire on the Democratic Party, with the best-known member of the so-called "Squad" of diverse and progressive House members urging her own party to have "the courage to brawl" against Republicans. And Sanders and Cortez took to the stage at their first stop in Las Vegas, Nevada, while...