If you follow politics and policy, you’ve probably heard the phrase “Common Core.” You probably also know that it has something to do with education policy. Perhaps you’ve seen posts on Facebook making fun of its new approach to solving math problems. And if you’ve been following the nascent campaign for the Republican presidential nomination, you might know that Common Core standards are a touchy issue for tea party and conservative voters.

But what exactly is Common Core, why do we have it, and what are the problems and political pitfalls?

Why Common Core?

Relative to other advanced countries, education in the United States has two major problems.

First, American kids are toward the bottom end of achievement among economically advanced countries in terms of academic skills. That’s bad enough. But what makes that problem difficult to solve is the federalist character of the United States education system where states have had broad leeway to set their own standards for educational achievement and proficiency. This is problematic for two reasons: first, the patchwork system of state-based education policies makes it difficult to improve education nationally, and second, state standards are often low as compared to what the federal government would like to see.

To fix this problem, a coalition of nonprofits, education groups, and teacher groups collaborated on developing a new set of standards from kindergarten through high school designed to improve proficiency and college readiness. These standards, which were finalized in 2010, have come to be known as Common Core.

So, what’s in it?

Common Core establishes a standard of the proficiency students are expected to have in both math and English language skills at every grade level from kindergarten to 12th grade. If you had to distil the essence of the Common Core standards into one word, it would probably be “reasoning.” In English, Common Core tends to focus more on reading nonfiction and evaluating arguments. Students will focus more on analysis than narrative, for instance. In math, Common Core focuses not just on the formulas used to solve problems, but on understanding the underlying theory behind why shortcuts and formulas work like they do.
This concept, though, has left Common Core math open for ridicule. The focus on theory can make simple arithmetic into a complicated experience. Take for instance, this famous example of what a simple subtraction problem can look like using Common Core techniques: it may build a stronger foundation for more advanced math later, but it doesn’t seem to be the most efficient way of accomplishing the task at hand.

One important thing to keep in mind: Common Core sets the standards for what students are expected to know on a grade-by-grade basis, but the curriculum by which those standards are achieved are still in the hands of states and local school boards.

Is Common Core mandatory?

No, adoption of the Common Core standards isn’t mandatory—but they’ve been adopted by 43 states as well as the District of Columbia. Primarily, that’s because the federal government has given strong incentives for states that adopt “college- and career-ready standards.” Now, states can still get that money by developing standards other than Common Core and getting them evaluated and approved by the Department of Education, but the Common Core standards come pre-qualified and don’t have to be designed from scratch, which makes them a much more enticing offer for states looking to fund their education systems.

What are the complaints about Common Core?

There are worries from both the right and the left, but for different reasons. On the left, there are concerns that the Common Core standards are too dependent on standardized testing as a method of evaluating students. In addition, there has been a movement to use this same type of standardized testing as a method of evaluating teachers: so-called “education reformers” and advocates for charters schools and against teachers unions tend to favor high-stakes standardized testing to evaluate teachers and use the results to argue for a weakening or elimination of tenure practices. While education advocates on the left don’t necessarily oppose the reasoning behind the new standards, they are wary about the possible consequences behind an increasing reliance on standardized tests.

The attacks against Common Core from the right are a different story. Conservatives tend to be more skeptical of increasing federal involvement in education, and feel that it will serve as a pretext for the federal government—especially under a Democratic president—to impose ideologies that conservatives may not agree with. Conservatives tend have more of a federalist outlook that seeks to devolve as much control as possible to local governments. Senator Ted Cruz (R-Tex.), a Republican presidential candidate who is a favorite of hard-right tea party groups, has already called for a repeal of Common Core on the misguided grounds that it constitutes a federal takeover of education curricula. (Common Core, by the way, isn’t a federal law—it’s just a group of standards states are choosing to adhere to.) Former Florida Governor Jeb Bush, however, is a supporter of Common Core standards—which could cause him trouble among more conservative voters in the upcoming Republican primary.

Is Common Core working so far?

Depends on how you measure it. Two states—Kentucky and New York—have started the process of using Common Core standards in their tests. Unsurprisingly given the higher standards at work, scores are way down compared to previous standards. But there is some evidence that adopting a Common Core curriculum is accomplishing its objective of getting students ready for college: in Kentucky, which was the earliest adopter of Common Core standards, the number of students needing remedial college courses in English have dropped in half.

How will Common Core affect the 2016 race for president?

As mentioned, it will have an impact in the Republican presidential primary: voters and activists in primaries tend to be more conservative and will likely be more skeptical towards candidates who support the implementation of Common Core standards.

On the Democratic side, likely Democratic nominee Hillary Clinton has endorsed Common Core, calling it a “wonderful first step in the right direction” toward improving American education. In the general election, differences on Common Core will be just one of many significant issues that separate the Democratic and Republican nominees.