The emerging national dialogue about making community colleges as free as K-12 education shows how central these institutions have become to our national vision for building a strong economic future. With nearly half of all U.S. undergraduates enrolled in community colleges, we must all agree on this fact: Our nation needs community colleges to be the best they can be. They simply cannot fail.

The announcement in March of the Aspen Prize for the best community colleges in America sends a critical message: If community colleges succeed as we know they can, they will provide an on-ramp to the middle class for millions and millions of Americans. Fifty years ago, Diablo Valley College in Contra Costa County put George on the path that eventually led to law school and the U.S. Congress.

Here’s what we know from our years as leaders in American education:

Labor market needs are changing. By 2020, more than 60 percent of all jobs will require a college degree or other post-secondary credential.

Community colleges today enroll 7 million degree-seeking students, more than a third of whom are the first in their family to attend college. Unfortunately, fewer than half of all community college students graduate.

While many community college degrees and certificates help students land jobs with strong wages — in areas such as nursing, welding and information technology — others result in jobs that pay wages barely higher than those earned by high school graduates.

The changing landscape of higher education has resulted in an increasingly diverse (and often less academically prepared) student body, less funding and greater accountability for student results than ever before.

The whole point of the Aspen Prize is to help change the definition of excellence in the field — and showcase examples of colleges that meet it. That means doing more than providing broad access and offering a wide variety of vocational and academic credits. The Aspen Prize winner and top finalists show that broad access can be maintained at the same time community colleges achieve unusually high — and dramatically improving — levels of student success.

As co-chairmen of the jury that selected the winners, we came to learn what the most innovative community colleges are doing to achieve outstanding outcomes — a set of “best practices,” which is a template for the 1,123 peer institutions in this country.

Santa Fe College in Florida, the national prize winner, shows how a community college can help students transfer to a four-year school and receive a bachelor’s degree at rates more than double the national average. And how a college can work with local employers to cut their training costs and fill available jobs faster.

Lake Area Technical Institute, in South Dakota, achieves strong employment outcomes for its students. Its 73 percent completion rate is higher than the vast majority of four-year colleges and universities. Local businesses clamor for Lake Area graduates, and they earn nearly 50 percent more than other new hires in the region.

West Kentucky Community and Technical College shows that it’s possible to attain high graduation and transfer rates without any achievement gap for minority students.

And Aspen’s Rising Star winner Kennedy-King College in Chicago shows how rapid reinvention can — in one of the most challenged neighborhoods in the city — triple a community college’s graduation rate in just a few years.

These community colleges are reinventing what colleges do to ensure all students reach their goals. They are building clearer pathways to jobs with family-sustaining wages. They are seeing big gains in student completion, both at community college and after transferring to four-year colleges. They are making sure students are engaged in rigorous learning so they have the knowledge and critical thinking abilities needed to succeed. And they are aligning workforce education with the rapidly changing skill sets students need to get jobs that provide pathways to the middle class.

We need more colleges across the country to achieve success for many more students. That means delivering more degrees of higher quality at a lower per-pupil cost to a more diverse population. We know it can be done, because there are model colleges that are doing it well.

For policy makers on all levels, it means supporting evidence-based innovation in community colleges. The best community colleges are showing how innovation can be the economic engine going forward for our nation’s middle class.

George Miller represented California in the House of Representatives from 1975 to 2015, and chaired the House Education and Labor Committee. Mitch Daniels is president of Purdue University and a former governor of Indiana. They are co-chairmen for the Aspen Institute Prize for Community College Excellence.