There’s an old saying in war and in politics: the enemy of my enemy is my friend. For Mayor Brandon Johnson, understanding that might just be the secret to getting reelected — something that once seemed unfathomable.

When Johnson made a Sunday pulpit appearance in May at Apostolic Church of God in Woodlawn, he hadn’t set out to become a target of Donald Trump. But when he boasted of having six Black officials in his cabinet and increasing opportunities for Black contractors, the MAGA outrage machine went into overdrive: End Wokeness, an anonymous account, posted Johnson’s remarks on X, where they were viewed a million times, including by the assistant U.S. attorney general for civil rights, Harmeet K. Dhillon, who retweeted them with the comment “No bueno.” The next day, Dhillon wrote a letter to Johnson, promising to investigate his administration for racial discrimination, even invoking the Civil Rights Act of 1964.

It was an extraordinary escalation stemming entirely from social media outrage. But Johnson, for his part, didn’t back down: He called Trump a “monster” who “would much rather have administrations that reflect the country club, period.” Clifford Zimmerman, a civil rights expert at Northwestern’s Pritzker School of Law, tells Chicago that the Justice Department’s probe has no chance of standing up in court: “All this is saying is you’ve ID’ed people who were Black in your administration. It doesn’t say he hired them because they were Black.”

However flimsy the case, the clash served a purpose for both Trump and Johnson: It’s red meat for their political bases. MAGA doesn’t like Chicago and its lefty mayor. Johnson’s voters don’t like Trump. Win-win.

For a mayor with an approval rating of less than 7 percent at the time, whose reelection had already been written off by many political observers, the chance to get on the president’s bad side was a political gift. The only politician less popular among Chicago voters than Johnson may be Trump. By pursuing a decidedly anti-MAGA agenda — openly promoting diversity efforts, standing up for undocumented immigrants, and firing back at the president — Johnson is making himself an enemy of Chicago’s enemy. As The Wall Street Journal’s conservative editorial board asked after the kerfuffle over Johnson’s comments: “Is President Trump making an in-kind donation to Chicago Mayor Brandon Johnson’s re-election campaign?”

The city of Chicago, of course, has long been a foil for Trump. But Johnson hadn’t personally been in his cross hairs as much as some other Democratic politicians, not least Governor JB Pritzker. Whether for reasons of principle or politics, Johnson hasn’t backed down after the Trump administration’s threats. In June, he went on the offensive, encouraging Chicagoans to demonstrate against raids by Immigration and Customs Enforcement. Calling Trump a “tyrant,” he urged “all of Chicago to resist in this moment,” because “whatever particular vulnerable group is being targeted today, another group will be next.” Johnson also vowed to refuse ICE requests for data on immigrants who applied for benefits through the CityKey ID program. Chicagoans seem to be responding: A new poll, released in mid-June, showed the mayor’s approval rating sharply higher, at 26 percent.

Just as beating up on Chicago is good politics in Trump world, getting on Trump’s bad side could boost Johnson’s chances in the 2027 mayoral election, says local political strategist Jake Lewis: “2026 is going to be all about Trump, 2027 is going to be all about Trump. The question is going to be: Who is best positioned to push back on Donald Trump? Whether it’s immigration, attacks on environmental regulation, abortion, this mayor has shown his values are aligned with the city. Now, can he effectively use the levers of government to push back against the feds?”

That will be key. Every mayoral candidate in the 2027 race — anyone who wants to win, anyway — will be able to say they’re anti-Trump. But if Johnson can point to specific policy wins, that would give him a much-needed edge.

Just look at other states. In California, Governor Gavin Newsom, thought to be eyeing the White House in 2028, dared Trump to arrest him and sued the president over federalizing the National Guard in Los Angeles to crack down on protests over Trump’s deportation efforts, calling it “an unmistakable step toward authoritarianism.” That has raised Newsom’s stock as a presidential contender.

“Trump’s antics will help Brandon,” says longtime political strategist Delmarie Cobb. What happened in Los Angeles is just one front in Trump’s ongoing campaign against America’s largest cities, which gives mayors the opportunity to step into the ring with Trump — and into the spotlight with their constituents. “That puts Brandon in a more advantageous position,” Cobb says. “Can he elevate his profile just like Gavin Newsom and [Los Angeles Mayor] Karen Bass?”

But Becky Carroll, a public affairs and communications consultant who worked in Mayor Richard M. Daley’s administration, is skeptical that picking fights now with Trump will benefit Johnson in an election two years away. She thinks that voters will ultimately focus on the totality of Johnson’s four-year record. “This is going to be one moment in time of a hundred,” Carroll says. “I don’t think people vote on a moment in time. Voter memories don’t stick around too long. Using [a conflict with the president] for your own political gain is not a winning strategy.”

And indeed, there’s evidence that tangling with the Trump administration gets you only so far. In New Jersey, the mayor of Newark, Ras Baraka, was arrested during a protest at an immigration detention center. While it undoubtedly boosted Baraka’s profile, even translating to a polling surge in the gubernatorial primary, it wasn’t nearly enough to get him over the line: Baraka won 20 percent of the vote — good for second place but 13 points behind the winner.

Likewise, standing up to Trump isn’t the only issue on which voters will judge Johnson. They care about crime, which is going down. They care about property taxes, which are going up. But now Johnson at least has a potential path to reelection, which he didn’t have before.

Good politics often consists of choosing the right enemies. Johnson didn’t even have to do that. In this case, the right enemy chose him.