The major significance of charter schools is hotly debated between liberals and conservatives. Conservatives typically support the idea of charter schools while liberals typically oppose them.
To their supporters, charter schools will improve the quality of education. They will do this in at least two ways. First, they will provide more innovation than the public schools will. They will be run by people with new ideas, thus breaking education out of its old ways. Second, they will force public schools to change by providing competition. Public schools will have to improve or face losing all their students to charter schools.
To their detractors, charter schools are an irresponsible experiment that will dilute education and ruin public education. They feel charter schools will dilute education because they will be run by amateurs who do not really know what is best for students. They also feel that charter schools will ruin public schools. They will do so by taking resources away from them at a time when public schools need more resources.
The significance of charter schools, then, is not completely knowable. We know that they are a source of controversy, but we do not know whose vision of charter schools is closer to the reality that will result if such schools become common.