President Obama took office in 2008 after making campaign promises to reform the nation's broken immigration system.
But he quickly decided that reforms would have to wait. Contentious battles with an ideologically divided Congress over health care reform and the budget pushed immigration issues to the side.
The president gave up on Congress and used the power of his office to make two major policy changes that will touch the lives of millions of immigrants...
Deportations soared under the Obama administration, and arrests along the United States-Mexico border fell as fewer migrants tried to enter the country illegally.
President Obama couldn't get Congress to budge on comprehensive immigration reform. But he used his executive power to implement rule changes that make life easier for American families with an undocumented relative.
And he also gave the children of undocumented immigrants -- the DREAM Act generation -- a major concession. He said his administration would suspend deportations and allow them to stay in the country under a "deferred action" policy.
Vice President Joe Biden has been the administration's most vocal supporter of the DREAM Act. He says it "makes no sense not to educate everyone in the country."
Biden's wife Jill, a college professor, is just as outspoken and committed to passing legislation that will allow undocumented students to go to college and pay lower tuition rates. He has been a frequent critic of states such as Arizona and Alabama that have written their own restrictive immigration laws.
The vice president would play a central role in pushing immigration reforms through Congress in a second Obama term.
In August 2011, Homeland Security Secretary Janet Napolitano announced major changes to the federal government's Secure Communities program.
Napolitano said the government would review 300,000 deportation cases to make sure it was concentrating on removing undocumented immigrants with serious criminal records.
The change was hailed by immigrant advocates and Hispanic groups who had complained about the program's deportations of workers that had no criminal records. Deportations fell after the change. Still, the Secure Communities program has no shortage of critics. Partnerships between federal, state and local authorities have been difficult to forge and just as hard to maintain.
In his first three years as U.S. attorney general, Eric Holder has had to challenge state lawmakers over their restrictive immigration bills.
His office has filed suits to block laws in Arizona, Alabama, South Carolina and Utah. Holder has argued the administration's position that the power to enforce immigration law rests solely with the federal government.
He has also had to defend himself against congressional attacks over the botched “Operation Fast and Furious” gun trafficking sting that led to the death of a Border Patrol agent in 2010. Some lawmakers accused Holder of not being forthcoming to Congress about the failure.
Born in Havana, Cuba, Alejandro Mayorkas became director of U.S. Citizenship and Immigration Services in August 2009.
Mayorkas has the difficult job of making the policies set by Congress and the president work in practical terms on a daily basis. He believes he has made significant improvements in communications between his office and immigrant communities during his tenure. He has tried to make the government's services more accessible to the people who need them, not always an easy job when dealing with diverse populations and cultural hurdles.