Obama Tells 7-Year-Old America "No Longer What it Once Was"

What's interesting is while Obama is shy about attacking or using negativity against his opponnet, he and his wife both seem eager to attack and use negativity against America every chance they get. Instead of saying he's running because he loves his country he says America isn't what it was. I wonder when America was? During the primary he refused to aknowledge the country had done well under the Clintons, so which time period was better? The Reagan years?