(New York Times) — President Obama created a grant program to copy his block-by-block approach to ending poverty. The British government praised his charter schools as a model. And a new documentary opening across the country revolves around him: Geoffrey Canada, the magnetic Harlem Children’s Zone leader with strong ideas about how American education should be fixed. Last week, Mr. Canada was in Birmingham, England, addressing Prime Minister David Cameron and members of his Conservative Party about improving schools. But back home and out of the spotlight, Mr. Canada and his charter schools have struggled with the same difficulties faced by other urban schools, even as they outspend them. After a rocky start earlier this decade typical of many new schools, Mr. Canada’s two charter schools, featured as unqualified successes in “Waiting for ‘Superman,’ ” the new documentary, again hit choppy waters this summer, when New York State made its exams harder to pass.