A gentle reminder when talking about about the presumptive Democratic nominee for President, from someone who doesn't talk politics here:

Referring to someone by their last name is generally a sign of respect. Referring to someone by their first name is generally a sign of intimacy. Consider how people have referred, in short form, to other nominees and Presidents:

Bush, Clinton, Gore, Bush, Kerry, Obama, Romney, McCain, Biden, Trump

And then

Hillary and Kamala

See a pattern?

@Impossible_PhD I've seen some authors use a first name is a uniquely humanizing way.

Best example was Hallie Rubenholds The Five about the five women the ripper killed. This was probably because their surnames changed multiple times over and Polly, Annie, Elisabeth, Kate, and Mary Jane works better, but also it was as you said, intimate as most people know them as just victims.

But when it comes to our (hopefully) next president, its all Harris to me.