TALLAHASSEE, Fla. (AP) — Jeb Bush's signature achievement in education policy as Florida governor may be faltering.

Bush championed what became known as Common Core education standards, and as governor achieved a set of high-stakes tests for students and a system of grading schools. They became the centerpiece of an education agenda that defines much of his legacy in office.

In the Republican presidential race, any mention of Common Core is a red flag for conservatives. Bush rarely talks about it by name as he campaigns.

But he's not backed down on what is the core of Common Core — the conviction that states need to raise school standards.

In Florida, a troubled rollout of standardized testing linked to the standards has many parents and school superintendents pressing for the regimen to be junked.