DURHAM, N.C. — President Barack Obama promoted job creation in politically important North Carolina Monday, trying to assure Americans he's focused on their No. 1 concern — and his greatest political weakness — as his potential GOP presidential opponents prepared to target his economic policies in their first major debate. [snip] "I am optimistic about our future," the president said, even while acknowledging that "we can't be complacent." Obama announced details of a program to train 10,000 new American engineers every year, saying private companies will join the government to promote education in science, technology, engineering and math. They'll offer...