Make no mistake about it, what President Obama has decided in his immigration executive action speech is a life changer for millions.

As he stated, "We were strangers once too" in a remarkable speech that pleaded for American understanding of the need to address the immigration issue.

Unless you have ever been illegal you will not fully comprehend what is at stake.

The fear of that knock on the door from “La Migra,” the fear that every time you go outside, or drive, or take a plane, or pass a security checkpoint that you will be discovered is very real, even if the chances are slim.

That nightmare is now over for those who qualify. Also, the fear of being cast in one of the dreadful immigration holding jails, where people can often disappear for months, is also over.

Now only criminal immigrants have something to fear which is a huge visceral relief to wives praying their husbands will come home from work, kids who fear losing their parents, families that fear being split up every day.

The good news is also that millions of immigrants, issued with a temporary work card, can now find jobs they are skilled at, not just with employers willing to take a chance on the undocumented.

For the American Treasury it will be a huge bonus as wages, taxes and social security will come in from the black economy to the mainstream.

That provision will especially benefit people like the Irish undocumented many of whom have college degrees but do not use them in their line of work.

In most states they will now likely be able to drive also – a huge relief for those who, up to now, have driven under others' licenses, taken cabs or public transportation.

It also appears to allow travel abroad in limited circumstances when conditions of "extreme hardship" prevail, though that needs to be fully explained. As always the devil will be in the details.

The down side is that anchor citizen children provision means that those who are here undocumented for many years but who do not have children are not part of the executive order.

That is discrimination of the worst kind and a heavy blow for such folk to receive no consideration in this executive action.

Also not addressed is the issue of travel, especially important in the case of Irish-born.

The reality is that this executive action is the beginning, not the end, of the process.

When Republicans get over their anger and admit there is no way to deport 11 million people, unless they want to bankrupt the government, maybe this executive action will shock them into real discussion on a comprehensive bill that can address all the issues.

Both sides are taking huge political risks here. President Obama may find himself isolated if the deep strain of anti-undocumented becomes a tidal wave – as it did some years ago on the issue of driver’s licenses.

The GOP could surely kiss goodbye to the Hispanic vote if they move aggressively against that community and seek to defund Obama’s executive order.

The game is back on for immigration reform. In September a New York Times survey showed 70 percent of the American people stated they wanted a resolution of the issue. Obama has put himself on the line to do so – now it is up to others to follow.

The outcome of Obama’s historic speech should be a comprehensive immigration reform bill in 2015.

President Barack Obama's speech marks the beginning of a long process of immigration reform.White House