Where's the tipping point in public education?

South Carolina's SAT Scores Fall

And it's not just because a high percentage of SC student's take the test. A higher percentage of students in sixteen other states take the test, and we trail all but one of them.

Plus the problem is not just at the bottom in South Carolina.
The better educated a SC student’s parents, the further he trails peers nationally. Actually, student at the bottom score on par with their peers across the country, though we do have more students in poverty. But the gap in test scores is greater with SC students at the top compared to their peers across the country.

This comes on the heels of reports that over half the high schools students in South Carolina do not graduate on time.

I wonder where the tipping point is for a large segment of folks decide that what we doing now is broken and we need to reinvent public education as we know it.