There has been no significant movement toward federal immigration reform since a bipartisan effort died in 2007, blocked by conservative opposition. But it has been the subject of a fever of legislation at the state level, and it could become an issue in the 2012 presidential campaign.

In December 2011, the Supreme Court agreed to decide whether Arizona may impose tough anti-immigration measures. Among them, in a law enacted in 2010 and challenged by the Obama administration, is a requirement that police in Arizona question people they stop about their immigration status. The ramifications of the court’s decision for immigration policy; for other states; and possibly for presidential politics are far-reaching.

Federal judges have now struck down portions of state immigration laws in Alabama, Arizona, Georgia, Indiana, Utah and South Carolina. But not all rulings have favored immigrants’ rights groups. In Alabama, a federal judge upheld the majority of the state law.

In a sense, legal experts say, these lower court battles are merely prologues to the Supreme Court decision.

The Obama administration has steered clear of making a push for comprehensive legislation to address immigration reform. Instead, to the dismay of Hispanic supporters, the administration has focused on a stepped-up campaign of deportation. President Obama’s enforcement strategies have led to more than 1.1 million deportations since the beginning of his term, the highest numbers in six decades.

Yet the administration has made it clear that its goal is to quickly deport convicted criminals, while in many cases halting the deportation of illegal immigrants with no criminal record.

The Obama administration’s tough approach to law enforcement and deportation has met resistance even among its usual allies. Democratic Governors from Massachusetts, Illinois and New York — states with large immigrant populations — have decided not to participate in Secure Communities, a fingerprint-sharing program.

Illegal Immigration Decreases; Tensions Remain High

The impact of steep declines in the number of migrants illegally crossing the border with Mexico in recent years has rippled across Arizona and other border states, with federal and local law enforcement seeing big drops in crime related to illegal immigration.

In Arizona, federal agents have found far fewer drop houses, where smugglers stash border crossers. Police chiefs in Arizona cities say their crime rates are low and are falling, along with the numbers and costs of illegal immigrants coming through their jails.