Democratic presidential candidates (L-R) former tech executive Andrew Yang, South Bend, Indiana Mayor Pete Buttigieg, former Vice President Joe Biden, Sen. Bernie Sanders (I-VT), Sen. Kamala Harris (D-CA) and Sen. Kirsten Gillibrand (D-NY) take part in the second night of the first Democratic presidential debate on June 27, 2019 in Miami, Florida. Drew Angerer | Getty Images

When 20 Democratic presidential candidates descend on Detroit this week, expect sparring over whether a major U.S. industry should even exist. Health care — particularly the question of whether America should adopt a universal single-payer system or take more modest steps to expand coverage — has towered over every other economic issue early in the 2020 Democratic primary. In the weeks since the first debate in June, two top-tier candidates — former Vice President Joe Biden and Sen. Bernie Sanders — have publicly litigated whether the U.S. should scrap its private insurance industry in order to cut costs. Based on the previous debate, health care isn't the only economic or business issue likely to emerge on Tuesday and Wednesday in Detroit. Expect Democrats to take shots at the 2017 Republican tax cuts for corporations and most individuals — and promise to repeal some benefits for businesses and the wealthy. In addition, watch for whether major issues that saw little discussion in the first debate get more time this week. Candidates barely talked about tariffs, trade and manufacturing in Miami. But the topics sit more toward the front of voters' minds in Michigan. President Donald Trump narrowly won the key state in 2016 in part by arguing the U.S. needs to overhaul its trade relationships to protect U.S. manufacturing workers. Here are some of the top business and economic issues to watch in this week's Democratic presidential debates:

'Medicare for All' and private insurance

The Biden and Sanders discussion over the best health care path for the U.S. is only the most prominent example of a debate that has raged throughout the primary. As two of the top candidates in nearly every primary poll, Biden and Sanders have come to represent two popular planks in the health care discussion: incremental steps to cover more Americans versus tossing out the private insurance system to ensure everyone gets insurance through a government plan. The health-care industry makes up about a sixth of the U.S. economy. When Biden unveiled his health care plan earlier this month, he cast the Sanders-backed Medicare for All as an effort to "get rid" of the Affordable Care Act. He argued the U.S. should not start "from scratch" and get "rid of private insurance," but instead expand coverage beyond the law known as Obamacare by giving Americans the option to buy a public plan. Other candidates such as South Bend Mayor Pete Buttigieg, Sen. Amy Klobuchar, D-Minn., and Sen. Michael Bennet, D-Colo., have endorsed a public option. Just days after Biden outlined his proposal, Sanders vouched for Medicare for All in a speech. Facing criticism from other candidates, he cast it as the best way to cover all Americans and reduce overall costs, while expanding the services covered by insurance. Sanders is the leading advocate for Medicare for All in the primary, and only a couple candidates have wholeheartedly endorsed his vision — which includes effectively dismantling private insurance. When asked at June's debate whether they would get rid of private insurance, only four candidates — Sanders, Sens. Elizabeth Warren, D-Mass., and Kamala Harris, D-Calif., and New York City Mayor Bill de Blasio — raised their hands. Harris is a candidate to watch in the second debate. On the day after the debate, she said she misheard the question and does not actually want to get rid of private insurance. But it's unclear how Harris, a sponsor of Sanders' Medicare for All bill, would implement such a system without effectively scrapping private plans. Surveys about Medicare for All partly explain the politics. Public support for Medicare for All has grown in recent years, but falls when respondents are told it would dismantle private insurance, according to Kaiser Family Foundation polling. So which candidates specifically could butt heads over health care on the debate stage this week? Sanders and Warren could find themselves defending single-payer repeatedly on Tuesday, the first of two debate nights. The stage features public option supporters in Buttigieg and Klobuchar. Former Rep. Beto O'Rourke, who has shown skepticism about Medicare for All after previously supporting it, will also participate in Tuesday's debate. So will former Rep. John Delaney, who has repeatedly criticized Medicare . Biden and Harris will share center stage on Wednesday night. Two sponsors of Sanders' Medicare for All bill — Sens. Cory Booker, D-N.J., and Kirsten Gillibrand, D-N.Y. — will also participate on Wednesday. They, like Harris, have shied away from calls to get rid of the private insurance industry.

GOP tax cuts

Democrats used the 2017 Republican tax law as a punching bag in the first debate as they tried to cast themselves as better champions for the working class than Trump has been. Expect more of the same in the second debate. Criticizing the law, which was expected to disproportionately benefit wealthier Americans, isn't only a way for Democrats to portray Trump as out of touch with ordinary Americans. Candidates have also pledged to reverse the tax cuts to fund plans to rebuild U.S. infrastructure and curb climate change, among other measures. In some of their first comments in last month's debate, Biden and Harris went after the GOP tax plan. The former vice president said he "would be going about eliminating Donald Trump's tax cut for the wealthy." Harris said that, "on day one, [she] will repeal that tax bill that benefits the top 1 percent and the biggest corporations in America." A day earlier, O'Rourke started his time on the debate stage by criticizing what he called a "tax cut that favored corporations while they were sitting on record piles of cash and the very wealthiest in this country at a time of historic wealth inequality."

Trade wars and manufacturing