Bad timing for Democrats: The gross national debt is set to hit $16 trillion Tuesday as the party’s convention gets under way, and Republicans are pouncing. “This is a grim landmark for the United States,” Alabama Sen. Jeff Sessions, the top Republican on the Senate Budget Committee, said in a statement. “That’s more government debt per person than Portugal, Italy, Spain or Greece. Yet the president seems strangely unconcerned.” In an interview on Fox News Sunday, Obama senior campaign adviser David Axelrod said the president’s economic plan would lower deficits by $4 trillion over a decade. But moving too aggressively,...