Sen. Tom Carper is not happy with the Postal Regulatory Commission. More evidence of that fact emerged during yesterday’s confirmation hearing for Tony Hammond, nominated for another term on the five-member oversight body. The session before the Senate Homeland Security and Governmental Affairs Committee lasted less than an hour; Hammond, a Missouri Republican who has served on the commission for most of the last decade, is likely to win easy Senate approval for another six-year stint. But Carper, D-Del., took the occasion to ask again why the agency can’t move faster in issuing advisory opinions on proposed changes to national…