FILE - In this March 22, 2013 file photo, Sen. Tom Harkin, D-Iowa speaks to reporters on Capitol Hill in Washington. Senate Democrats are introducing legislation that would replace the one-sized-fits-all national standards of No Child Left Behind with ones that states write for themselves. Harkin on Tuesday was ready to announce a bill that drops some of the education law's requirements that critics said were unrealistic, such as a 2014 deadline for students to perform at grade level in math and reading. Instead, states would write their own improvement plans. The proposed system is similar to one Education Secretary Arne Duncan already has in place for 37 states and the District of Columbia. Those states received waivers to the requirements in exchange for customized school improvement plans. Credit: AP