- In a Subjunctive Mood -

From the NY Times style book:

If the bill were passed, taxes could go down (not was passed, because it is still just a hope).

I think this is incorrect reasoning. True, the bill has not yet passed; but it might. In that sense, it is not contrary to fact in the strong sense of "If I were you..."—always an impossibility. Thus, the subjunctive here should (I think) be reserved only for a bill whose passage seems reasonably unlikely. Note: this is a confusing example because the relationship between the bill and taxes is also conditional.