This question already has an answer here:
When I need to focus on a specific instance of a subject, but want to include a clarifying remark making it plural, I may set off that secondary statement like this:
The state of Florida (and 27 other states in the US) has/have Right-To-Work laws.
I'm not asking about parenthetical pluralization where you add an optional (s) to the subject when the quantity is not known (e.g. vendor(s) as in this post), but a clarifying statement that is part of the subject (or maybe it isn't; that's what I'm asking).
So is the subject of this sentence above singular or plural? Which is the correct usage in my example?