They marched on City Hall to deliver a simple message – “This is our home now.” I walked out and welcomed the one million people who showed up on my doorstep. I looked out on the crowd – a mayor for less than one year – and told them “I don’t see any illegals! No human being is illegal. No human being should be illegal.” They may have come here illegally, but they also came for a better life and most have contributed much to this nation.

I took a lot of heat for that. But an immigration policy that allows us to grow together and not apart is the moral and economic imperative of our time.

For too long Washington has pushed immigration reform off until the next election. Too often, the issue is punted to the next Congress. Now is the time for us to say enough is enough. When we reform our broken immigration system, we will not only restore the most basic of American covenants, we will give this economy a much needed shot in the arm.

When the head of a household becomes a citizen, family income rises almost 14 percent on average. For the 11 million undocumented immigrants in the U.S. that would generate over $1.5 trillion in the next decade. And for the federal government that would mean $4.5 billion in new tax revenue over the next three years alone.

But the long-term effects are even greater. Today, 40 percent of Fortune 500 companies were started by immigrants or by the children of immigrants. These companies have combined revenues of $4.2 trillion. For those keeping score that’s more than the GDP of every country in the world except the U.S., China and Japan.

The success of our immigration system goes hand in hand with the success of our broader economy. That’s why the time to act is now. Our action should be based on our core principles and values, through six broad policy pillars:

One – A pathway to legal permanent residency and citizenship for the 11 million undocumented immigrants must be at the core of reform.

Two – Legalization should be earned, but not unattainable – a process not a punishment. You should have to go through a criminal background check, learn English, and pay back taxes.

Three – Family unification should continue as a key priority of our immigration policy. The goal must be to protect the sanctity of the family. Keeping families together not only keeps capital in the United States, it also maximizes the potential that these immigrants start family-based small businesses and grow our economy. Despite the economic benefits and moral imperative, millions wait over two decades to be reunited with family members. This must change.

Four – The hard work and talent of immigrants fuels our economy. Our immigration policy must expand the avenues for these valued workers to seek legal employment. As the president has suggested, let’s staple a green card to the diplomas of foreign students getting advanced degrees in science, technology, engineering and math. We need to expand the H1-B visa program and, at the same time, we need effective visa programs for agricultural workers and for low-skilled, non-seasonal workers.

Five – Immigration reform must include an effective and efficient employment verification system. Such a system can and must prevent unlawful employment, reward those employers and employees who play by the rules and protect Americans’ fundamental rights.

Six – We must protect our border through smart enforcement. According to the Migration Policy Institute, immigration enforcement takes the lion’s share of federal law enforcement spending. Today, net undocumented migration is at or below zero. It’s time we realize that we will not meet our immigration challenge through enforcement alone.

Based upon these principles and pillars, let’s make 2013 the year when we welcome 11 million people out of the shadows. Let’s make 2013 the year that we all agree immigrants don’t deserve half a handshake – they deserve a full embrace.

After all, the American Dream doesn’t just belong to some of us. It belongs to all of us.

Antonio R. Villaraigosa is the mayor of Los Angeles and the former president of the US Conference of Mayors.