Heh. It must be having an effect on his campaign if he brought it up.
So, yeah, technically, that particular sentence which came out poorly in a grammatical sense... I buy he was refering directly to roads and bridges. But it is quite clear from the full context around the sentence and the many times this argument has been made by him and his cohorts -- is that BECAUSE you didn't build the roads and bridges, and you USE the roads and bridges, we are justified in confiscating as much of your profits as we think is "fair". In other words, "you didn't build that". Huh. Exactly the way it came out.
And they will never say how much that is, because if they get a dollar today, they'll want two tomorrow, and three the next day, and so on, and so on, and so on.
So at best, I'd call it a revealing slip of the tongue, what he and his academically infused ilk might perhaps call Freuedian.
Update: This rather illustrative photo has been circulating. North Korea builds roads, too.