It’s because the media backlash came after he made that comment about Mexicans and he didn’t back down. I remember a lot of people saying, “that’s what I love about Trump. He doesn’t take shit from anybody.”

This was during a right-wing backlash to perceived political correctness and people being forced into apologies for “wrong think.” Same reason someone severely lacking charisma like Jordan Peterson gained a following.

Then the media kept going and Trump continued telling them to fuck off. Nothing riles up chuds more than a guy who tells the MSM to fuck off.