Can the US support 300 million people?

Can the US support 300 million citizens? Accordng to this story, probably not:

The danger, experts say, is that the US may simply have postponed the day of reckoning. Major environmental problems remain, and some are getting worse - all of them in one way or another connected to US population growth, which is expected to hit 400 million around midcentury. Some experts put the average American's "ecological footprint" - the amount of land and water needed to support an individual and absorb his or her waste - at 24 acres. By that calculation, the long-term "carrying capacity" of the US would sustain less than half of the nation's current population.
"The US is the only industrialized nation in the world experiencing significant population growth," says Vicky Markham, of the Center for Environment and Population, a nonprofit research and advocacy organization in New Canaan, Conn. "That, combined with America's high rates of resource consumption, results in the largest ... environmental impact [of any nation] in the world."