Updated

Presidential contender Barack Obama on Tuesday called for a $18 billion education plan that he said would fix mistakes his chief Democratic rivals made when they approved President Bush's "No Child Left Behind" effort.

The Illinois Democrat criticized Sen. Hillary Rodham Clinton and former Sen. John Edwards for not fully funding No Child Left Behind. While outlining his own education proposal to prepare students for college and to train teachers to lead in classrooms, Obama said the two rivals haven't done enough to protect students.

"It's pretty popular to bash No Child Left Behind out on the campaign trail, but when it was being debated in Congress four years ago, my colleague Dick Durbin offered a chance to vote so that the law couldn't be enforced unless it was fully funded," Obama said. "A lot of senators, including Senator Edwards and Senator Clinton, passed on that chance. And I believe that was a serious mistake."

Obama's plan would encourage universal pre-kindergarten programs — but not require them — expand teacher mentoring programs and reward teachers with increased pay not tied to standardized test scores. Failing teachers would be moved from classrooms and replaced with ones who are competent, Obama said.

"In this election, at this defining moment, we can decide that this century will be another American century by making a historic commitment to education. We can make a commitment that's more than just the rhetoric of a campaign, one that's more than another empty promise made by a politician looking for your vote," the Illinois senator said.

Obama's plan would cost $18 billion. His campaign said he would pay for it by delaying NASA's Constellation Program, which is developing the vehicle and rockets to go to the moon and later to Mars, by reducing costs by buying in bulk, by auctioning surplus federal property and by cutting down erroneous payments identified by the Government Accountability Office.

Obama said families also have to be part of the solution.

"We can spend billion after billion on education in this country. We can develop a program for every problem imaginable and we can fund those programs with every last dime we have. But there is no program and no policy that can substitute for a parent who is involved in their child's education from day one," he said.

Obama said he would accredit college programs, remove poorly performing teachers from classrooms and increase time spent on math and science instruction. He said mentoring programs are key to keeping good teachers involved and improving struggling ones.

He said he also would establish 40,000 new scholarships for potential teachers, pay for continuing education programs and invest in new schools.