If elected president, Senator McCain would support private school vouchers, give full funding to the federal No Child Left Behind law, and push for an expansion of “virtual schools,” the Republican candidate said yesterday in unveiling his education plan during a speech to the NAACP.

The promise to “fully fund” No Child Left Behind was a departure; previously Mr. McCain has said he would freeze nondefense discretionary spending, including spending on education.

The speech was a chance for Mr. McCain’s campaign to try to shape him as the 2008 race’s more serious proponent of education “reform” of the sort President Bush touted when he ran for office promising to be the education president.

In it, Mr. McCain criticized Senator Obama for saying in a speech to the American Federation of Teachers that support for vouchers is “tired rhetoric.”

Vouchers are scholarships that allow parents to send their children to private schools at the government’s expense. They are bitterly opposed by teachers unions.

“All of that went over well with the teachers union, but where does it leave families and their children who are stuck in failing schools?” Mr. McCain said.

In a conference call with reporters yesterday, an aide to Mr. McCain framed Mr. Obama’s position on vouchers as a reversal, suggesting that he switched to being opposed to vouchers from being in favor of them because of pressure from teachers unions. The aide referred to Mr. Obama’s “decision to change his position on vouchers.”

Evidence that Mr. Obama supported vouchers is sparse. He repeatedly voted against tuition tax credits as a state senator in Illinois, calling them a “back door” voucher, and in 2004 he told the Chicago Daily Herald that a voucher program would “drain” public school resources.

However, Mr. Obama raised eyebrows when he told a Milwaukee newspaper’s editorial board in February that, though he was a skeptic on vouchers, he was surprised to learn there had been no definitive study to assess whether vouchers improve student learning.

“If there was any argument for vouchers, it was, ‘Let’s see if the experiment works,'” Mr. Obama said. “And if it does, whatever my preconception, you do what’s best for kids.”

Mr. Obama’s campaign quickly backpedaled, saying Mr. Obama had always opposed private school vouchers.

Mr. McCain downplayed his own support for vouchers. The only voucher proposal in his education plan was a declaration of support for the voucher program in Washington, D.C. Instead, Mr. McCain’s plan focused on politically safer options, such as charter schools and bonus pay for teachers.

The executive director of Democrats for Education Reform, Joseph Williams, said the proposal was a smart move by Mr. McCain. “We are watching McCain take a stab at winning the sensible middle — and that should have been Obama’s territory,” Mr. Williams said. “This puts some pressure on the campaign to redefine Obama as the candidate of change.”