What percentage of straight men would rape women under "ideal" circumstances?

There appear to be a lot of rapists who do not understand that they did in fact harm their victims, even when any reasonable person would recognize the situation as a clear-cut case of violent stranger rape. Many of these rapists seem to consider a woman who eventually stops struggling to be the same thing as a woman who freely consents to sex. I’m going to quote myself here from a GQ thread last month: