Now that the intense media coverage of new U.S. Education Secretary Betsy DeVos is over, could we please turn our attention to a little-noticed threat to our most effective high school classes?

Congress congratulated itself last year when it passed the bipartisan Every Student Succeeds Act (ESSA). But its Republican and Democratic sponsors failed to say they were blindsiding teachers and students responsible for a remarkable surge of academic depth in high schools.

The most challenging courses in American public education have been expanding rapidly since the federal government in 1998 began subsidizing disadvantaged students’ exam fees in college-level courses, particularly the Advanced Placement (AP) and International Baccalaureate (IB) programs. In 2016, 941,557 AP exams were taken by students from low-income families.

At that moment of startling success, the congressional sponsors of ESSA killed the program. Nobody knows yet what will happen as the students scramble to find money for those tough exams in May.

Many people know how prized AP and IB courses are in suburban schools. Students who want to attend selective colleges essentially have to take them. Most of their parents and schools can afford the fees, $93 for the three-hour AP exams and about $116 for what are often five-hour IB exams.

But few people have witnessed the transformation that comes from bringing AP and IB into disadvantaged schools. Go into high schools like Wakefield in Arlington County, Columbia Heights in the District, Mount Vernon in Fairfax County, Foshay in south-central Los Angeles or Young Women’s Prep in Miami and you see kids on fire — asking questions, arguing historical points and polishing their writing.

IDEA Public Schools, a charter network in Texas that enrolls mostly low-income students, has AP test participation rates at some campuses twice as high as affluent public schools such as McLean or private institutions such as National Cathedral School. How will their students handle fees far above the $5 to $15 per test they have paid in the past? “If we take away the reimbursement for the AP test, we take away a powerful incentive that moved more kids to test,” said Tom Torkelson, chief executive of IDEA Public Schools.

“Our experience tells us that there will be many students who will not register for exams if support for test fees is not available,” said Colleen Duffy, a spokeswoman for IB.

The College Board has been encouraging low-income student participation in AP for more than 30 years, beginning with its embrace of East Los Angeles mathematics teacher Jaime Escalante. Escalante and a teacher he trained produced 26 percent of all Mexican American students in the country in 1987 who passed an AP calculus exam. Escalante showed that such results were possible if teachers gave more students more encouragement and time to learn.

Trevor Packer, the College Board vice president who oversees AP, said there are “more than 500,000 low-income students sitting in AP classes now who are affected by the funding changes.” The College Board has increased its low-income subsidy from $22 to $31 per exam, which totals more than the former federal subsidy. But it still has to pay for expert human graders who are much more expensive than the machines that score multiple-choice state tests, or the SAT and ACT.

Some Washington-area districts, including the District, Prince George’s County and Charles County, say they will protect disadvantaged students from increased fees this year. Nineteen states are using their funds as a stopgap this year while seeing how much money will be available from underfunded federal block grants which AP and IB have to share with dozens of other programs, but most states haven’t done much.

Escalante’s students held carwashes to pay for tests. Such old-fashioned funding may be necessary. Rich folks like DeVos could put their money where it would do immediate good if they asked local public schools how to support teenagers who need to more money for those big tests.