I've gained first hand knowledge of the challenges faced by people with disabilities. It's made me understand that those of us who have full use of our physical faculties owe an enormous amount of respect and sensitivity to people who don't.
Nearly every problem has been solved by someone, somewhere. The challenge of the 21st century is to find out what works and scale it up.
I challenge every business person in America who has ever complained about the failure of the welfare system to try to hire somebody off welfare. And try hard.
Our overriding environmental challenge tonight is the worldwide problem of climate change, global warming, the gathering crisis that requires worldwide action.
Though our challenges are fearsome, so are our strengths. Americans have ever been a relentless, questioning, hopeful people.