He is probably there for a VP candidate - and was probably asked to do this by party leaders. The popularity of Trump will black voters - especially MEN - will sink the Dem candidate in the 2020 general election. Trump’s border issue resonate with many blacks thinking of themselves as AMERICANS; like others, they are tired of being surrounded by people jabbering in foreign tongues. For blacks in particular, many of these foreign scabs end up as their supervisors; the animosity is palpable (both ways).
The party leaders looked for the best token and came up with him.
You may be right. Give Fauxahontas a black face on her flank.