In the heat of the presidential primary season - and at most other times, too - it seems as if Republicans and Democrats can’t agree on anything. But although they may disagree vociferously on everything from tax policy to foreign conflicts, President Obama and the Republican candidates seem to share the common conviction that it is not just desirable but a matter of urgent national concern to revitalize US manufacturing.In the heat of the presidential primary season - and at most other times, too - it seems as if Republicans and Democrats can’t agree on anything. But although they may disagree vociferously on everything from tax policy to foreign conflicts, President Obama and the Republican candidates seem to share the common conviction that it is not just desirable but a matter of urgent national concern to revitalize US manufacturing.