Dismal news about U.S. public education keeps tumbling in, but Congress seems unable to act and Republican presidential candidates seem determined to have America keep slipping behind the rest of the world.

And the Obama administration, which previously sparked dramatic state action for school reform, is showing signs of letting up the pressure.

After nearly three years of talk, Congress has failed to renew and reform President George W. Bush’s No Child Left Behind Act that mandated school reform. Citing Congressional “dysfunction,” President Barack Obama has controversially imposed his own program by executive order, but some reformers say it’s significantly weaker than NCLB.

And despite evidence that public schools are underserving all income groups, GOP presidential candidates all want to “get Washington out of education” — several of them by dismantling the U.S. Department of Education — thereby undoing national pressure for change.

At NBC’s two-day Education Nation conference that I attended in New York last week, not one of 10 governors on a panel — including conservative Republicans from Wisconsin, Virginia, Oklahoma and Alaska — supported ending the DOE.

As noted in the NBC conference’s program, “Compared to the rest of the world, U.S. high school students rank 14th in reading, 17th in science and 25th in math — at or below the international average in all three subjects.”

That’s familiar bad news, along with the fact that only 73 percent of young people graduate from high school on time — and only half of minority kids, America’s future majority — though two-thirds of future jobs will require post-secondary training.

In the past month, more unsettling reports have come in. New Scholastic Aptitude Test results showed only 43 percent of kids intending to go to college are actually prepared for college work. ACT exam results put that number at just 25 percent.

The Organization for Economic Co-operation and Development reported, also in September, that the United States has fallen from 12th to 16th in the percentage of young adults holding college degrees, trailing even Russia.

In an interview in New York, the president of the National Education Association, Dennis Van Roekel, told me that America’s rankings would all be world class if poor kids were not counted — bolstering the repeated union claim that it’s poverty, not bad teaching, that’s the problem.

But that argument is exploded by two new studies that ought to land like bombs among U.S. policymakers. Third Way, a centrist think tank, reported that middle-class schools score behind both upper-income and poverty schools in average teacher salaries, per-pupil expenditures and class size, and get only 28 percent of their graduates through college.

And, finally, the George W. Bush Institute just released a Global Report Card showing that even the very wealthiest schools and districts in the country — including Beverly Hills and Palo Alto in California and Fairfax and Montgomery counties in the Washington, D.C., suburbs — score no better on math, science and reading tests than average schools in 25 developed countries.

A few very high-income or highly educated districts scored at the top of the rankings, but the most encouraging finding was that so did charter schools in Massachusetts, New York City, Delaware and North Carolina that serve low-income students.

It’s the case made repeatedly in journalist Steve Brill’s powerful new book, “Class Warfare,” and repeated often at NBC’s conference: What kids of all incomes need to succeed is high expectations, good teachers and principals, demanding curricula, longer school days and years — and power in the hands of school administrators to reward and fire teachers based on student performance.

As Brill points out, all that has been clear ever since the Reagan administration’s famed 1983 report, “A Nation at Risk,” which — besides sounding its famous alarm bell — called for better pay for teachers, but also standardized tests and tying salary, promotion, tenure and retention decisions to “effective evaluation systems.”

Brill’s book is a history of the three-decade effort by heroic reformers — resisted every step of the way by the NEA and the American Federation of Teachers — to turn those recommendations into local, state and national policy.

Every administration since President Ronald Reagan’s has stepped in the right direction, but Bush and Obama finally got somewhere. Bush’s NCLB policy, passed on a bipartisan basis, and Obama’s Race to the Top demanded and incentivized state action to raise standards, test all children, report the results, expand charter schools and institute pay-for-performance programs.

NCLB called for all American children to be “proficient” — meaning college- or workforce-ready — by 2014. That’s obviously not achievable, and there’s widespread agreement that the law needs to be rewritten lest up to 80 percent of schools get labeled failures and have federal aid jeopardized.

But Congress and the Obama administration have been talking NCLB reform for three years and nothing has happened. So Obama and Education Secretary Arne Duncan acted unilaterally to offer states waivers from NCLB in return for promises that they will keep standards up.

Reformers such as former Clinton White House aide Andy Rotherham fear that the waiver plan lacks teeth and allows the states to backslide. Republican reformers such as Sen. Lamar Alexander (Tenn.), a former Education secretary, are determined to give the states even more leeway.

“Fundamentally, both the administration and Alexander are making a bet that transparency and shame are enough to force people to do the right thing,” Rotherham told me. “I’m not sure what political system they’ve been studying to reach that viewpoint — certainly not ours.”

As Duncan told the NBC conference, “the country is paying attention” to school reform, “but we’re not at critical mass. I’d like voters to go to the polls with education as their No. 2 or No. 3 priority, not No. 5, 6 or lower.”

Indeed. And before the elections, Congress should take Obama’s waiver plan as a prod to sustain real reform by law.