Greenwire: In the three months since a ruptured pipeline sent more than 800,000 gallons of oil into his district’s waterways, Rep. Mark Schauer (D-Mich.) never strayed far from the spill response and won GOP support for safety reforms. But those efforts are nowhere to be found in his re-election rhetoric. Locked in a rematch with ex-Rep. Tim Walberg (R-Mich.) for Michigan’s 7th District, Schauer leads with bread-and-butter economic issues — manufacturing, Social Security, trade with China — …