The Texas Legislature opened in January with students, parents teachers and school administrators across the state clamoring that making youngsters pass a nation-leading 15 state-mandated standardized tests to graduate high school was far too many.

While some leading business groups worried that watering down high academic standards would leave students ill-prepared for the demanding jobs of tomorrow, the sustained backlash against too much testing largely drowned them out -- and lawmakers listened.

Facing a midnight deadline, the House and Senate were set to vote late Sunday to slash the standardized tests required in high school by two thirds, from 15 to five. And they were poised to overhaul the state curriculum, allowing some students to graduate without having to take Algebra II or other advanced math and science classes.

Both chambers also faced votes to dramatically increase in the number of charter schools allowed to operate statewide, increasing the current cap of 215 to 305 by September 2019.

Gov. Rick Perry has not commented, but is expected to sign the overhaul into law when it reaches his desk.

Sen. Dan Patrick, a tea party Republican from Houston who chairs the Senate Education Committee, campaigned for months to erase entirely the charter cap, and to create a special board to approve a flood of new charter applications he expected would follow.

But the final bill is far more modest, encouraging gradual growth and leaving the ability to approve new charters in the hands of the governor-appointed state commissioner of education.

It also makes it easier for state authorities to close down poor-performing charters. That's important because, while many existing charters are among the state's highest-preforming campuses, schools with low academic ratings are also disproportionately charters.

Opponents had questioned why Texas needs to approve expansion when so many of the existing charter schools are struggling.

While increasing charters schools, and therefore giving parents and students more "school choice" was Patrick's crusade, the testing and curriculum shakeup was championed by Killeen Republican Rep. Jimmie Don Aycock, head of the House Public Education Committee. It is designed to give more flexibility to students who want to focus on vocational training that would better prepare them for high-paying jobs that don't require a college degree.

The proposal supplants a 2007 law that created curriculum standards mandating that high school students take four years each of math, science, English and social studies. Instead, it would let them earn a "foundation" diploma without so many core academic courses, thus allowing more space for career-training electives.

It also creates a "distinguished" high school diploma for students who complete Algebra II and other upper-level math and science courses. Doing so qualifies them for automatic admission to any Texas state university -- just as all those who graduate in the top 10 percent of their high school classes do now. Those who don't earn distinguished degrees wouldn't qualify for automatic admission.

Still, critics, including many higher education leaders, say the proposals would essentially lower the bar for many students by enabling them to graduate without really challenging themselves. They point to studies that show a correlation between being able to pass Algebra II and succeeding in college and beyond -- and say that as many young people as possible should take it.

The testing changes would mean only exams in Algebra I, Biology, U.S. History and English I and II remain. Testing on English reading and writing, which had been given separately, would be combined. The measures also mandate that the state eventually continue to produce tests in Algebra II and English III -- but they will be optional for school districts to administer, and won't count toward a school or district's accountability rating scale.

Meanwhile, the state currently has 209 charters. Because operators can use a single charter to run multiple campuses, though, Texas has about 500 total charter schools educating more than 154,000 children, or 3 percent of its 5 million-plus public school students.

Sunday's proposal would free up a lot of extra space, something advocates say is vital since around 100,000 students from across the state are on waitlists for charters that don't have the space to accommodate them.