After meriting a couple of momentary mentions during the primary season, the “Keating Five” scandal — the 1980s savings-and-loan debacle that Sen. John McCain once called the biggest mistake of his career — now has surfaced again in all its ugly glory. As global financial stability today teeters on the edge of collapse, those looking for reasons leading to the present meltdown should take a close look at the Republican presidential candidate’s regulatory philosophy over his quarter-century in Congress and his role in the infamous S&L scandal.