Andrew Friedman is executive director of the Center for Popular Democracy and an adjunct professor at New York University School of Law. Nisha Agarwal is deputy director of the center and a lecturer at Columbia School of Law.

The legal issue before the Supreme Court this week is whether to uphold certain provisions of Arizona’s anti-immigrant legislation. S.B. 1070, which passed in 2010, requires local law enforcement to determine people’s immigration status and arrest individuals suspected of being undocumented. It also criminalizes immigrants’ failure to carry “registration” cards or attempts to solicit work.

It would be a devastating blow to equality and civil rights in this country if the justices allow Arizona’s law to stand. But whatever the outcome, immigrant and civil rights advocates should act on a lesson we have avoided absorbing for too long: that efforts toward equity and inclusion must be made in states and localities, not merely in Washington.

Laws such as Arizona’s are part of an explicit strategy of attrition through enforcement designed to make life in this country close to impossible for immigrants, particularly Latinos. They are akin to Jim Crow-era laws that cultivated a climate of fear in communities of color throughout the South.

A question raised by the Arizona case is the extent to which states and cities can regulate immigration. The high court acknowledged “the supremacy of the national power in the general field of foreign affairs, including immigration,” in the 1941 case Hines v. Davidowitz. But what precisely this means has become murky over the years. The Supreme Court found in 1976 that not every attempt to regulate immigrants is necessarily a regulation of immigration, and the justices have upheld state laws relating to the employment of undocumented immigrants in California ( De Canas v. Bica ) and Arizona ( Chamber of Commerce of the United States v. Whiting ). A panoply of federal policies — including Secure Communities, a program that allows state and local police to check an individual’s fingerprints against Department of Homeland Security databases, and the Criminal Alien Program, through which federal immigration agents are allowed into local jails to screen for undocumented immigrants — has further complicated matters by actively engaging states and localities in federal immigration enforcement. One aspect of federal law, section 287(g) of the Immigration and Nationality Act, even delegates authority to local law enforcement to make determinations related to immigration.

As the federal stronghold on immigration policy and its implementation has weakened, state and local laws, many of which are hostile to those new to this country, have sprouted. The National Conference of State Legislatures reported in December that in the first 11 months of 2011 about 1,600 bills and resolutions related to immigration were introduced in the 50 states and Puerto Rico, and more than 250 of those were enacted. Arizona’s S.B.1070 and copycat bills such as Alabama’s H.B. 56 are just the highest-profile local efforts to “crack down” on immigrants.

But there is no reason state and local interventions on immigration must be punitive. Some jurisdictions have begun to shape their laws to create more welcoming communities. Many legislators understand the value of promoting trust and cooperation between government and the governed. Cities such as New York and Chicago and smaller places such as Santa Clara, Calif., have opted to resist increasingly harsh federal immigration enforcement by prohibiting local law enforcement from subsidizing federal deportation policy. After the DREAM Act failed in Congress last May, California and Illinois passed their own legislation, and campaigns have taken hold in other states, including New York, Colorado and Pennsylvania, to promote access to higher education for undocumented young people.

The Arizona case underscores the urgency for even more state and local efforts to promote equity and opportunity. Steps should be taken to end racial profiling but also to expand integration of immigrants — improving access to education and health services, for example — and legal protections for low-wage workers. Advocates of immigrant and civil rights should be asking: What, and where, is our anti-Arizona legislation?

Yes, there can be dangers when states seek to take over areas of traditional federal authority. Nonetheless, if the Supreme Court approves of states’ rights to legislate in this area, it is essential that supporters of equity and inclusion reclaim this terrain. Defending immigrant communities from racial profiling is not enough. We must also work to promote opportunity wherever possible and to create the welcoming society that that United States has always aspired to become.