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First, the 2020 presidential campaign has begun. The likely candidates are giving media interviews, meeting with potential campaign aides and donors, and planning their campaign themes. Many voters and writers, meanwhile, are asking what kind of nominee the Democrats should choose next year.

My column today addresses that question. I think many of the most frequently discussed topics — a candidate’s race, sex and age, for example — are overrated. But I do think there is clear evidence about what kind of campaign the Democrats should run.

It should be a populist campaign — one focused on jobs, wages, health care and education, a campaign that takes on President Trump, congressional Republicans and corporate lobbyists for harming the middle class. Populism has enormous political potency right now, and my column tries to make the full argument for it — with help from history and charts.