DES MOINES, Iowa -- Elizabeth Warren says she has more than 1,000 campaign staffers in 31 states and 100-plus field offices, a show of organizational strength her campaign promises will lift her to the Democratic presidential nomination and hurt President Donald Trump’s chances in key battlegrounds in November. The Massachusetts senator vows that her campaign will be organized in all 57 states and territories before the Democratic National Convention in July. In the meantime, it’s looking beyond Iowa, New Hampshire, Nevada and South Carolina, which open the primary, and “Super Tuesday” on March 3 when more than a dozen states...