The New York State Democratic Party, which struggled for decades to win a working majority in the state Senate, finally did so in last week’s election, winning 40 of 63 seats. Sen. Andrea Stewart-Cousins will be majority leader.

Perhaps the most important story inside the story is the diminished power of Sen. Simcha Felder, a Brooklyn Democrat who caucused with — and cynically collected favors from — the Republicans in exchange for enabling them to hold onto power. In addition to moving forward on a previously stalled policy agenda, the new majority should reverse the harm done in the last legislative session.

In March, as a condition to backing the budget as a deadline approached, Felder used his influence to force an amendment creating a carve-out for ultra-Orthodox yeshivas to receive preferential treatment under the “substantial equivalent” standard of instruction that all private and parochial schools must provide under the state’s education law.

Felder’s amendment didn’t go through any normal deliberative process, and the public was not aware of it until five days before it passed as part of the budget. It has no conceivable purpose other than to lower the instructional bar for ultra-Orthodox yeshivas below that for other private schools, so there will be no consequences for them continuing business as usual.

Indeed, supporters of these yeshivas, including the leader of the Satmar Hasidic sect, Grand Rabbi Aaron Teitelbaum, have said as much.

In an interview with Ami Magazine, a widely read publication in the ultra-Orthodox community, Teitelbaum revealed that religious leaders, working in concert with Felder, exploited Gov. Cuomo’s desire to have a budget passed on time to ram through the yeshiva exception.

This amendment was not on the agenda of either Democrats or Republicans, but was submitted and passed at the behest of special interests such as the Satmar Rabbi and Agudath Israel.

The timing was no accident. In recent years, state and city officials have faced mounting calls from yeshiva graduates like myself and the general public to address this issue.

The state was in the process of revising enforcement guidelines when the Felder amendment threw their efforts into disarray, and now the city is facing difficulties in getting yeshivas to cooperate with its own inquiry.

While many yeshivas in the city comply with the law, with some even offering a superior curriculum to public schools, thousands of children (especially boys) attend Hasidic yeshivas that offer little instruction in English, math, social studies and science. Once these students enter high school, secular education often vanishes completely.

This lack of education results in poverty, with the Hasidic enclaves of Kiryas Joel and New Square ranking among the poorest areas of the country.

While supporters of yeshivas counter with individual examples of successful alumni, the data paint a starkly different picture for the vast majority who graduate from these schools unable to write and unfamiliar with basic mathematical and scientific concepts, rendering them unqualified for most jobs and higher education.

The educational neglect of Hasidic children is not a new problem, but it should be of great concern to legislators who have long been committed to social justice, children’s rights and reducing economic inequality.

While I believe the Felder amendment is unconstitutional and should be invalidated in federal court, a route the group I lead is currently pursuing, it is ultimately the Legislature’s responsibility to ensure it does not pass unconstitutional measures.

This amendment embodied a particular low moment in Albany’s history of backroom dealing. The rights of children were sacrificed on the unholy altar of political convenience.

This problem remains a moral emergency. Begin to fix it by reversing Felder’s meddling.