Donald Trump has become the main character again, for better or worse.

One of the former president’s political superpowers has always been his ability to command attention and dictate the topic of our national debate. He outrages, and we follow along.

But from her electrifying debut through her strong performance at the debate, Democratic nominee Kamala Harris had managed something none of Trump’s previous challengers had: She stepped out of his shadow and set the tone of the race. She was not just playing a supporting role in his drama.

Trump changed the subject from his poor showing at the debate to detestable and false claims about Haitian immigrants.

That is now over. Like only he could, Trump changed the subject from his poor showing at the debate to detestable and false claims about Haitian immigrantsrefocusing the race on his favorite subject.

Is this a good thing? There is a theory that the more voters see Trump, the more they will remember why they dislike him. That may yet prove true.

But it is also true that setting the agenda is crucial in any election. In this view, if immigration becomes the central issue over the next six weeks — even if it’s due to ridiculous claims — then that is bad for the vice president.

Harris is running a good campaign. But it has become a cautious one. Interviews are scarcelittle is unscripted. And we know that if there is a void, Trump will fill it.

Harris has shown us she has main character energy, too, and she would benefit from asserting it again. Because it is a huge risk to let Trump write the story of this campaign.

Brendan Buck

Brendan Buck is an NBC News and BLN political analyst. He was previously counselor to former House Speaker Paul Ryan and press secretary to former House Speaker John Boehner.