The ranks of America's poor are on track to climb to levels unseen in nearly half a century, erasing gains from the war on poverty in the 1960s amid a weak economy and fraying government safety net. The AP surveyed more than a dozen economists, think tanks, and academics, and found a broad consensus: The official poverty rate will rise from 15.1% in 2010, climbing as high as 15.7%. Several predicted a more modest gain, but even a 0.1 percentage point increase would put poverty at the highest since 1965.