President Barack Obama's job approval climbed to 52 percent in the Gallup poll for the three-day period of Sept. 4 through Sept. 6, which is the highest Obama's approval has been since the three-day period ending June 1, 2011, when it hit 53 percent. On Sept. 3, the day before the Democratic National Convention started, Obama's approval had been just 45%. At the same time, Obama picked up ground over Republican presidential candidate Mitt Romney. Last week, according to the Gallup tracking poll of the presidential race, Romney actually lost a point over the course of the Republican National Convention....