When does the morally right thing to do become the wrong thing to do (see details)?

There are some circumstances where doing the “right” thing can cause more damage and suffering than doing the “wrong” thing. But does the amount of suffering caused by keeping the moral high ground ever make it morally wrong to do the thing that is supposedly right?

Easy example: You about to go through a green light. The idiot in the oncoming car makes an illegal turn, pulling out right out in front of you. Technically you have right-of-way, and by rights you ought to crash into the side of his car. However, you hit the brakes instead, sparing both you and the idiot an accident and a bunch of hassle. Even though you were right, it would have been wrong to do.

Medium example: President Nixon was about to be impeached for his role in the Watergate break-in. The country was horribly divided and tensions were running high. When he resigned instead, President Ford pardoned Nixon of any crimes he may have committed. Technically, Nixon was likely guilty of some pretty bad stuff, and legally and morally he ought to have been punished – but doing so would have caused strife in the nation when we needed to come together. In Ford’s mind, though, the desire to mend the country was the right thing to do, even though a criminal went free.

Hard example: Banks and investment firms that played with iffy financial instruments caused the meltdown and recession. Morally, they should have been allowed to sink, taking the economy with them. (At the beginning of the Great Depression, Hoover’s policies of allowing banks to fail and clamping down on the cash supply to “protect” the dollar made the Depression deeper and longer.) Bailing out at least some of the failing banks and issuing a stimulus package may have been “wrong” because it didn’t let the guilty parties fail, but would it have been moral to risk allowing the people to go through another Depression in order to punish the banks? The President thought not, and took action to alleviate the recession in ways Hoover didn’t.

I don’t want this question to devolve into a debate on traffic laws, Watergate, or God forbid, Obama and the bailout/stimulus. What I am asking is: when there’s a clear moral right way that also causes a whole lot of needless damage, how much damage must that be for the “right thing” to actually be the “wrong thing?” Or is the “right” thing always the right thing, no matter how much more suffering it causes?

Sorry it’s so long.