The next big effort by the populist movement to redeem the Democratic Party is Michigan’s Senate primary on Aug. 4, and this week’s debate between the two contenders illustrates the stakes. Abdul El-Sayed told viewers that he wants to abolish ICE, tax billionaire wealth at a fair rate (“let’s say an 8% tax”), freeze seniors’ property taxes, and offer universal childcare, plus government healthcare “without a deductible, a premium or a copay.”

The other thing he’s selling, though, is the long-overdue scrutiny of who actually runs this country, and the corrupt donor-class grip on our democracy. “For too long,” Mr. El-Sayed observed, “our foreign policy has been handed to us by the likes of the state of Israel and AIPAC,” the American Israel Public Affairs Committee. He promised to “stand up to the monopolies and oligopolies that are picking our pockets.” The Immigration and Customs Enforcement agency “is not about immigration,” he correctly said. “ICE is about normalizing paramilitary force on our streets.”

The other candidate, Rep. Haley Stevens, argued she’s a pliant legislator, unlike her opponent, whose primary business is mobilizing the public. “I am not trying to sell a book or a podcast,” Ms. Stevens said. “My head is down doing the work for the people of Michigan, who need the work to be done. We do not need a celebrity Senator. We need a workhorse.” She also claimed that she will do better in November against Republican Mike Rogers.

Ms. Stevens would also move the country toward the modest reforms a realigned donor class has grudgingly conceded. She endorsed further taxing the billionaire class and forcing them to pay their fair share, as well as uncapping the Social Security payroll tax, which currently shields the wealthy after the first $184,500 of earnings. Ms. Stevens wants to establish a national guarantee of paid family leave for workers.

She’s rightly opposed to President Trump and his push for mass deportation. “Donald Trump’s ICE is completely out of control, and it is an abuse of power,” Ms. Stevens rightly said. She introduced legislation in March to set up a necessary “independent special prosecutor.” She told the debate audience that Mr. Trump’s $70 billion ICE slush fund should be redirected to other law-enforcement agencies.

Is that enough for the Democratic base these days, or does it crave harder stuff? The debate moderators didn’t press Mr. El-Sayed on whether the abolition of ICE means a humane migration policy; whether he’d vote to make healthcare a guaranteed public right; or whether President Obama was an Israeli puppet, too.

But the demand for fairness is in the air after Democratic primaries in Washington, D.C., New York and Colorado. How about Michigan?