For politicians who claim to love the Constitution, Arizona Governor Jan Brewer and deposed former state senator Russell Pearce appear to have no problem disregarding it when it suits their purposes. With all of Pearce’s pouting and protesting in front of Senator Chuck Schumer and the Senate Judiciary Committee this morning–not to mention Brewer’s infamous tarmac finger-wagging incident with the President last January–it is tempting to dismiss their antics as political theater. But this isn’t just a political tussle with the Obama Administration and its allies. Brewer and Pearce are picking a fight with our nation’s founders.

The drafters of our Constitution, including James Madison and Alexander Hamilton, made it unmistakably clear that the federal government has the exclusive power to regulate immigration, and consider the foreign policy implications of how we treat non-citizens within our borders. The United States, not Arizona or any other individual state, makes our country’s foreign policy, and the founders could not have been plainer in their intent to ensure that the nation speak with one voice in foreign affairs. The Constitution features many areas where states can and should experiment with innovative policies; this is not one of them.

Indeed, Congress has emphasized the delicate balancing act required in the immigration arena by giving substantial discretion to the Executive to take into account a myriad of complicated, interwoven issues, including border security, humanitarian interests, civil liberties considerations, and the need to treat both citizens and migrants fairly under our laws. There are many important reasons the Executive may decide not to deport an otherwise removable person–for example, to grant political asylum, to allow a person to stay in the United States under the Convention Against Torture, to prevent exceptional hardship to an immigrant’s U.S.-citizen family members, or simply because scarce resources are better spent elsewhere.

Paul Clement, the superstar lawyer who recently turned the improbable arguments of the “Obamacare” challengers into a plausible Supreme Court case, has wisely argued in his Supreme Court briefs on behalf of Arizona that the state is “cooperating” with federal law and S.B. 1070 simply “mirrors” and implements federal law. Russell Pearce tried to make the same argument before the Senate Judiciary Committee this morning. But Arizona’s decision to pursue single-minded, aggressive, non-discretionary “attrition through enforcement” conflicts with the complex balancing act that the Constitution, and specific congressional enactments, have delegated to the Executive branch. Senator Schumer wasn’t buying it, pointing out that S.B. 1070 differs from federal law: in simple ways, such as accepting a more limited list of identification documents than federal law allows, and in more fundamental ways, by seeking to create such a hostile environment for immigrants (or basically anyone with “brown skin,” as former Arizona senator Dennis DeConcini put it during the hearing) that people “self-deport.”

The Supreme Court shouldn’t buy S.B. 1070 supporters’ claims either when it hears arguments inArizona v. United States tomorrow. The Constitution doesn’t allow states to set immigration and foreign policy, and it certainly doesn’t allow them to do so in a manner that discriminates against Latinos and other people of color.

Russell Pearce invoked “We the People” at this morning’s hearing–in a rather bizarre exchange about how S.B. 1070 gives “We the People” of Arizona the right to sue law enforcement officers who don’t maximally enforce the law–but he expressed an utter disregard for the Constitution that “We the People” have created. “We the People” came to together at the Founding to “create a more perfect union,” that included a federal government empowered to speak with one voice on immigration, naturalization, and foreign affairs. “We the People” added the Fourteenth Amendment to the Constitution after the Civil War, ensuring that all people within the borders of the United States–citizen or not–enjoy the “equal protection of the laws.” This morning, Pearce derided the equal protection concerns about S.B. 1070 as “silly arguments” from “open borders” advocates. The Constitution is not “silly.” It is the charter of our enduring federalism and the foundation for the pursuit of the American Dream in a nation of immigrants. When Brewer, Pearce, and their tea-party allies converge on the Supreme Court tomorrow, they should take a closer look at the pocket Constitutions they will no doubt be sporting.