As Guy noted in his wrap-up post, while Newt Gingrich took the brunt of the criticism in the Sioux City debate Thursday night (a memorable exchange with Michele Bachmann comes to mind) his rebuke of the President’s unyielding opposition to the Keystone XL pipeline was perhaps his strongest moment. Gingrich’s argument, essentially, was that the United States was missing a golden opportunity to create thousands of American jobs, address national security concerns, and mitigate our dependence on foreign oil. And yet, given his propensity to drop rhetorical bombs, Newt also showed uncharacteristic restraint by choosing his words carefully. Indeed, he argued his points vigorously, but didn’t use language that was overtly caustic or offensive. For the moment, it seems, the former House Speaker has allayed growing fears that he is incapable of controlling his temper on stage. Nonetheless, after pledging to run a “positive campaign” – and breaking that promise numerous times – one wonders how long this trend can continue.