Carlson has three advantages over Trump.
First, he doesn’t have a policy legacy that will need to be reoriented as time passes. For now, Trump’s approaches as president already meet with broad approval from his base. But over time perceptions tend to shift, as former president Barack Obama can readily attest. Carlson doesn’t need to worry about that. He does have a legacy of rhetoric, sure, much of which will age poorly. But that’s just words.
Second, Carlson seems less burdened by Trump’s tendency to moderate his stated views. Perhaps this is a function of their backgrounds: Trump, the salesmen, told people what he needed to. Carlson, the pundit, instead honed his arguments to sharp points. He still couches his words, certainly, but he seems to do so less to broaden his appeal than to draw his audience closer.
That audience is the third and most important advantage. Carlson has a nightly television show that attracts millions of viewers a month. Trump went from the pulpit at the White House to essential silence, booted from social media and relying on invites from people like Bartiromo and the general sycophancy of his old friends on the network to get in front of Fox viewers. Carlson speaks to his audience every night.