They're almost certainly going to pick someone centrist for the VP. Politico has a list of likely running mates [1]. They're pretty much all centrists.

Of course, whoever they nominate will just be called a leftist anyways. Even Harris is on the right wing of the Democratic party, and here you are calling her "left-leaning."

[1] https://www.politico.com/news/2024/07/21/harris-potential-vp...