SEATTLE, Wash. -

The Obama administration has exempted two more states -- Washington and Wisconsin -- from many requirements of the federal No Child Left Behind education law.

Now more than half of the states have received waivers, raising questions about the future of No Child Left Behind. President Barack Obama started granting the waivers this year to states that promise states to improve how they prepare and evaluate students.

It's part of an ongoing effort by Obama to act on his own when Congress is rebuffing him.

Education Secretary Arne Duncan says "our kids can't wait any longer for Congress to act."

The 10-year-old federal No Child Left Behind law requires all students to achieve proficient math and reading scores by 2014, a goal that many educators say is impossible.