According to a new Pew Hispanic Center report, illegal immigration has dropped by almost two-thirds in the past ten years. The numbers increased, but slowed from 2000 to 2007, while the numbers dropped by 300,000 from 2007-2009.

This is not a surprising trend. The Department of Homeland Security announced in early 2010 that the illegal population in the United States had dropped from 11.6 to 10.8 million from 2008-2009. The fledgling economy coupled with the institution of increased enforcement efforts during the Bush years have pushed illegals inside the United States to go home, while encouraging those thinking of entering illegally to think again.

The real message to these statistics, however, isn’t just that the population numbers are going down but that this data undermines a key argument of amnesty advocates. The amnesty crowd has built its case for “earned legalization” (aka amnesty) on the premise that the immigrant community inside the U.S. was largely immobile and highly rooted here, and that even with increased pressure through immigration enforcement, there was little likelihood that they would return to their home countries. They take it one step further and assert that the only solution is to let illegals have a path to citizenship.

With 300,000 individuals leaving in a period of two short years as a result of the economy and increased enforcement (enforcement that even the Obama Department of Homeland Security has touted as a success story), it is a tough-sell to say that the only option left is an amnesty. In fact, as opposed to enforcement, amnesty would make problems worse by simply encouraging more illegal immigration.

Despite real evidence that enforcement and economic disincentives have a major impact on illegal populations, the Obama White House has taken steps as of late to decrease, rather than increase enforcement. Changes to the 287(g) program that trained state and local law enforcement to enforce federal immigration law, an inherent border security policy, and the all out abandonment of several worksite enforcement policies, coupled with an assault on Arizona’s immigration law were bad enough. But now the Administration has taken to dismiss deportation cases against non-criminal illegal immigrants, allowing them to stay in the United States.

As my colleague Matt Mayer points out, “Instead of constantly seeking ways to evade, skirt, and ignore the immigration laws that are on the books, the Obama Administration needs to simply execute the laws—as is its constitutional duty—while looking to solve the immigration problem in a way that discourages more illegal immigration, maintains security, and promotes the economy.”