One of the hallmarks of populism is that it rarely represents mass mobilization simply for the people. It’s also typically mass mobilization against an opposing force — whether it’s the hated elite or the despised “other.” The for/against dynamic is inherent to some degree in all of politics, but mobilization against other people as a group is a core component of the populist enterprise.
Take, for example, old-school southern populism. Yes, there was a powerful economic component, often centered around government-sponsored economic development. But white southern populism was also focused directly and intentionally against black southerners. Despite the fact that they lived and work alongside southern whites, they were still the “other.” They were still the threat.
Much ink has been spilled analyzing Trump’s populism. And the for/against dynamic on the right is alive and well. If Trump’s appeal were based mainly around his calls for tariffs, his desire to retreat from the Middle East, or even his immigration restrictionism, he likely would have crashed and burned in the general election. Each of those positions is contentious within the Republican community, much less the nation at large.