Causality is often difficult to prove, but it doesn't stop people from trying. That "gay marriage" will destroy the institution itself is an oft-mentioned claim. The hows and whys are never delineated with any logic or reason, but those holding the view will often claim a "slippery slope." Which is deeply ironic, since slippery slope is the name of an illogical premise. Even better, there is now evidence that Massachusetts marriages are stronger than the rest of the country, five years after same-sex marriage was legalized.