An $82 trillion avalanche looms.

The American polity recently tore itself apart debating the morality of adding $1.5 trillion in tax cuts to the national debt. Yet the $82 trillion avalanche of Social Security and Medicare deficits that will come over the next three decades elicits a collective shrug. Future historians — and taxpayers — are unlikely to forgive our casual indifference to what has been called “the most predictable economic crisis in history.”

Conservatives used to prioritize long-term fiscal solvency. For years, Republican leaders from Newt Gingrich to Paul Ryan to Mitt Romney called for modernizing Social Security and Medicare before they collapse under the …