With the midterm elections just nine months away, the Democrats face some hefty existential questions that need answers: Who are they in this post- and possibly pre-Trump era of American politics? Are they simply the anti-Trump party? Or are they the party of progress? Who are the voters they need to turn out in November? Should they excite the base by building a coalition united against white supremacy, or should they moderate their message to win over Republican-defectors? This week on “The Argument,” Jane Coaston brings together two voices that represent the factions in the Democratic Party’s existential struggle. Lanae Erickson is the senior vice president of social policy, education and politics at the center-left think tank Third Way. She argues that Democrats need to make their platform as broadly popular as possible in order to bring more voters under the party’s big tent. That’s the way to win, and then enact progressive policies. Steve Phillips disagrees. He’s the founder of the political media organization Democracy in Color and author of the book “Brown Is the New White: How the Demographic Revolution Has Created a New American Majority.” He counterargues that the Democrats must run and win as the party united around a vision of a multiracial, just society, unapologetically calling out racism on the other side of the ticket.The two political strategists strongly disagree on what the party needs to do to win in November, but they agree on one thing: Democrats are afraid and need to answer the question of who they are, fast.