I think US may either do one of couple things.
1. Attempt at tighter restraints like economic blockades
2. Attack Iranian navy blocking strait, could escalate into war which is probably not wanted, so they would not do that
3. Do nothing and continuing doing point 1. Not react over it.
It is safe to assume that the US has enough gasoline reserves to not need Middle East oil. They are really doing this out of Christianity/Judaism. The idea of gasoline need is a false front given to fooling muslims. I mean, anybody can make ethanol out of free sunlight energy these days.