The number of illegal immigrants in the United States has dropped notably during the Obama administration -- from a high of 11.9 million in 2007 to 11.2 million in 2010.

That fact may be lost on many Americans in the din of presidential election rhetoric and the emergence of anti-immigration laws in several states where officials grew frustrated with what they perceived as the federal government's failure to enforce U.S. immigration policy.

Decreasing birth rates in Mexico and a weak U.S. economy are factors in the decline. The administration's aggressive deportation policy is a bigger factor, however.

The Obama administration has deported 1.2 million illegal immigrants, compared with the 1.6 million deportations during the eight-year Bush administration.

The idea that Obama is soft on illegal immigration simply isn't true.

The deportations are largely the result of two policy changes. First, instead of targeting workers in the kinds of chilling workplace raids favored by the Bush administration, Obama has cracked down on those employers that hire illegal workers -- an approach businesses dislike but one that draws bipartisan political support.

In addition, under a program known as Secure Communities, Obama has focused on deporting criminals. The program requires that the fingerprints of individuals booked at local jails be checked against Department of Homeland Security (DHS) immigration databases, a practice that has resulted in large numbers of deportations.

(The program isn't without flaws. In too many cases, the DHS data has been outdated or wrong. That sometimes has led to innocent people, even American citizens, being detained or wrongly deported.)

Despite the decline in illegal immigration on his watch, Obama's State of the Union address rightly called for comprehensive immigration reform, just as his predecessor, George W. Bush, had done. In fact, the last bipartisan attempt at major immigration reform collapsed under Bush in 2007.

Immigration is so politicized in this country that Congress seems unwilling to act. Politicians are entrenched along partisan lines that in some cases are at odds with their party's history. A decade ago, key Republicans championed the DREAM Act as a sensible but rigorous way to provide permanent residence to individuals brought into the country as children. DREAM Act legislation won the backing of Obama and most congressional Democrats last year, but it fell short in the Senate in the face of Republican opposition.

GOP presidential hopefuls Newt Gingrich and Mitt Romney support a scaled-back DREAM Act that provides a pathway to residency in exchange for military service. While a broader bill is better, if that narrower version would meet with bipartisan congressional support, the president should embrace it.

But Obama and Americans should reject Romney's call to make life so miserable for illegal immigrants that they flee the country -- what he calls self-deportation. Several states -- including Alabama, Arizona, Georgia, Indiana, South Carolina and Utah -- have embraced that approach and, in some cases, created frightening anti-immigration legislation harking back to the Jim Crow era.

Last month, the U.S. Justice Department issued findings of an investigation -- begun under the Bush administration -- that concluded that rogue Arizona sheriff Joe Arpaio committed civil-rights violations against Hispanic residents. This has to stop.

Humane answers can and must be found to address the millions of law-abiding immigrants who have lived in the country for decades, have raised families, have worked hard and have paid their taxes.

The longer those in Congress fail to work together to bring about reform, the more divided we become.