Immigration from Mexico plummeted well before Arizona law (interactive map)

The Supreme Court upheld the most controversial portion of Arizona's immigration law Monday, clearing the way for police officers in the state to ask about a person's immigration status during routine stops. Whether this tactic will deter future border crossings will be difficult to measure, however, because illegal immigration from Mexico has plummeted in recent years. There are many factors that have probably contributed to this decline, chief among them the fact that there are more border patrol agents on the ground and fewer jobs for those who do make it to America.

To visualize how dramatically illegal immigration has abated, Yahoo News teamed up with Michael Gastner, a junior research fellow at Imperial College London who specializes in creating maps that manipulate the shape of states to represent data. (One of his popular "cartograms," for example, uses physics equations to reshape the United States according to population density.)

In the interactive infographic below, we treat the border with Mexico like a rubber barrier that bends according to the pressure of immigration, as represented by the number of apprehensions in that region of the border. When the border bends way into U.S. territory, it represents a large number of people caught trying to cross illegally in that area that year. If it contracts back to its normal shape, it is because immigration is down for that year.

We've provided some data on the Border Patrol force and the economy for reference. Just click the bars on the chart to see the border bend for that year.