One of the most interesting exchanges at a pivotal Senate Banking hearing yesterday came when Sens. Brown and Warren pressed regulators on bank capital distributions. Each alleged that banks – especially way-big ones – pay dividends and repurchase shares to enrich shareholders at grave cost to struggling borrowers. Sen. Brown went further, arguing that banks should be barred from capital distributions if profits come from regulatory relief. Given the capital windfalls that analysts project from recent Treasury recommendations, Democrats are laying pipe for a stiff price they hope to extract from any big banks that reap benefits from regulatory rewrites. Should they get it?