Nothing fails like success nothing is so defeated as yesterday’s triumphant Cause.

McGinley’s aphorism captures the paradox that victory can contain the seeds of its own obsolescence. A “triumphant Cause” wins public assent, institutional power, or cultural dominance—yet the very fact of success can drain it of urgency, moral clarity, or adaptability. What was once a rallying cry becomes yesterday’s orthodoxy, vulnerable to complacency, internal faction, or changing circumstances. The line also suggests how quickly history re-sorts reputations: yesterday’s winners can look naïve or compromised once new facts, new values, or new crises arrive. In that sense, success “fails” by turning a living struggle into a settled, and therefore defeatable, past.