a Barack Obama

I notice that political commentators and pundits often use the expression "a Barack Obama" -- as in the question:

"Will white working class men vote for a Barack Obama?"

I know who Barack Obama is, but I'm not sure what "a Barack Obama" is.
(Who besides Barack Obama is "a Barack Obama?
If no one, why not just say "Barack Obama"?)

Usually, such an expression turns a name into a predicate, a description.

To say someone is "a Fred Astair" would be to say he's a great dancer.
To say someone is "a Harry Houdini" is to say that he is a magician or escape artist.

It seems that when you predicate a proper name of someone, you are saying that that individual possesses the salient characteristics of the bearer of that name.
(I hope that clears things up!)

So, what does it mean to say that someone is "a Barack Obama"?
What are Obama's salient characteristics?
What other words describe "an Obama"?
"...a senator"? "...a good speaker"? "a magnetic leader"?

Nah...
No pundit is going to bother to ask whether working class white men will vote for a senator, a good speaker, a magnetic leader, etc.

Given the contexts in which this expression appears, I think that "a Barack Obama" is a black guy with a funny name.

And I think that people that use that expression are raising the issue of race while trying not to be too obvious about it.

If I'm wrong, tell me what "a Barack Obama" is.

To be fair, people sometimes say "a Hillary Clinton," and even "a John McCain" once in a while.

I guess "a John McCain" is an old white Republican guy, but I'm not sure what "a Hillary Clinton" is supposed to be. Maybe a woman. "Former first lady" seems too particular.

My hunch is that, for the most part, media people started using those expressions after they started using "a Barack Obama" as a euphemism, and they do this to try to appear as if they are talking about all 3 candidates in the same way.

Though I'd have to go back and study the tapes to be sure.