Eliot Spitzer, former governor of New York, has a new calling: online commentator. At 5:59 p.m., Slate, the online magazine, published the first of what it says will be a series of biweekly columns by Mr. Spitzer on financial matters. Mr. Spitzer’s first column argues against using bailouts to prop up giant financial conglomerates, asserting that the money could be better spent elsewhere, whether it’s supporting “basic research and development that could give us true competitive advantage” or restructuring “our bloated health care sector.” The flaw in consolidation, Mr. Spitzer writes, is that it has created mega-banks that are deemed...