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The second round of Democratic primary debates begins tonight in Detroit, followed by another debate on the same stage Wednesday night. Most analysts expect confrontation, because these are the last debates before the standards for qualifying get tougher. Those candidates below the top tier will likely feel an urgency to stand out tonight and tomorrow — and to get the kind of attention that leads to donations and rising poll support.

Here’s what I’ll be looking for tonight:

Whom are Sanders and Warren pitching? The highest-profile candidates in this debate are Senators Bernie Sanders and Elizabeth Warren, and they are obviously competing for many of the same supporters. They’re also both virtually guaranteed to make the next debate. So I’m more interested in their overall approach than in any conflict between them. Both have organized their campaigns around a populist pocketbook message that is well-suited to win swing voters who supported Donald Trump in 2016 (and then swung back to the Democratic column in 2018). Those swing voters — like the American public as a whole — tend to be very progressive on taxes and other economic issues, favoring higher taxes on the rich and corporations, a higher minimum wage and expanded government health care. But I’ve been disappointed to see both Sanders and Warren go further this year and emphasize positions that most Americans don’t favor, like the forced elimination of private health insurance. Their message on immigration has also become less balanced than Sanders’s message once was, with virtually no discussion of border security. Tonight, I’ll be watching to see whether Warren and Sanders are more focused on Twitter Democrats or actual Democratic voters. Both senators became national voices by paying more attention to the latter.

The center lane. Many Democratic voters see themselves as moderates. They aren’t especially ideological and, more than anything, they want to beat President Trump in 2020. The fact that there are so many of these voters — roughly half of the Democratic primary electorate, according to Gallup — means there should be a place for a candidate who chides other Democrats for moving too far left on Medicare, immigration, free college and other issues. Tonight’s debate lineup, which was chosen randomly, happens to include most of the candidates who could play this centrist role: Senator Amy Klobuchar of Minnesota; Governor Steve Bullock of Montana; John Hickenlooper, the former Colorado governor; John Delaney, a former Maryland congressman; and Representative Tim Ryan of Ohio. I’m especially curious to see whether either Klobuchar or Bullock — who have the résumés and skills to be top-tier candidates — can have a big moment.

What’s Mayor Pete ’s plan? He is currently at the bottom of the top tier of candidates. One option is for him to keep doing what he’s been doing and put his hopes on slowly building support, especially in Iowa. Another option is to take on Sanders or Warren. I expect he will avoid big risks tonight, but maybe not; debates are fascinating in part because of the uncertainty.

Is Beto done? No 2020 candidate has been more disappointing than Beto O’Rourke. He looked like a top candidate when the campaign began. But his rollout was weak — too much glitz, not enough substance — and he has sometimes seemed halting on the trail. “Mr. O’Rourke has looked like what he is: a novice,” Mimi Swartz writes in a new Times Op-Ed. “Candidates to the left and the right of him have more experience, more knowledge and more ideas.” Presidential campaigns are longer than media pundits often suggest. But for Beto 2020, it seems to be getting late early.

For more …

George Will, in The Washington Post, suggests a list of tough questions for the candidates. Among them: Your positions seem to suggest that you don’t think Barack Obama accomplished much; is that true?

Julian Zelizer, a Princeton historian writing for CNN, argues that Warren’s task is to “consolidate the non-Biden Democrats, along with the marginal Biden supporters, around her candidacy. This means that in the debate her objective will be to keep making the case that she is the most credible coalition builder rather than the frontrunner.”