The emotional aspect of "nationalizations" is so strong that the subject can't be tackled by pointing how unsuccessful they are, but by reversing the emotions it evokes. People is proud of something labeled "national", which leads them to pardon unknown limits of deficit as long as the symbol holds strong. Since it's a matter of pride, as long as the symbol holds strong it will be associated with national identity, leading to people to feel attacked personally if you point practical problems of the scheme, so they will stubbornly reject it beyond reason. So what I like to do is to remember people that when something is "nationalized" it doesn't mean that it now "belongs to the people", but the exact opposite: what's "nationalized" has no more to answer to the market but to the state, thus not answering to the market means it no longer belongs to the people, and answering to the state means it solely belongs to corruption, for demand and rentability are no longer a metric to drive production but the political agenda and internal favours. So the proper strategy to break that spell is to dissociate "nationalization" with the idea of "identity", complemented with their inherent economical failure as the last nail in the coffin.