Okay, so the 12, or 15, or 20 million undocumented and illegal immigrants in this country get kicked back across the various borders tomorrow morning.

What then? Who’s going to pick up all those tools strewn on the ground? Who is going to perform all the tasks and jobs that were being performed from California to Maine by the suddenly absent?

Given that U.S. unemployment is not especially high right now, that would apparently mean precious few.

The current state of play is that the United States needs all hands on its decks and reporting to duty – and then some.

But not all hands will necessarily respond. Certainly, quite a few able-bodied Irish have given up and headed back to Ireland and elsewhere in recent years.

Not a few of them are currently shipping out to another familiar Irish destination: Australia.

The Irish Independent reported that Ireland is facing “a mass exodus of people looking to escape the crime and grime of modern living – and the slowing construction industry.”

Sure enough, there have been forecasts that the downturn in the housing market in Ireland would mean that many construction workers would not have jobs to return to after this month’s traditional summer break.

And the Irish among them – many such workers are of course immigrants to the island – are already looking Down Under as an escape valve.

“Figures show that up to 700 skilled workers a month are seeking visas to move Down Under, with many politicians bringing their families as well,” the Independent report stated.

Apparently, Australia is going through a boom, but has a dearth of professionals, which it is trying to shore up with workers from other countries.

“In particular demand are all types of construction workers, bakers, chefs, hairdressers, doctors, teachers and accountants,” the report added.

Australia is a big country with a sizable economy. But it is not the United States. At the same time, like America, it is a destination that is attractive to just about every nationality on the planet.

The Irish, however, enjoy certain advantages. As with the United States, a huge proportion of the Australian population, roughly one-third, is of Irish extraction.

There is a large and active Irish-born population in Australia’s main cities. There is even an Irish Echo newspaper (no relation) published in Sydney.

The lesson to be drawn from this new migration to an old destination is that people will move these days in order to simply advance up the economic ladder.

This means leaving jobs, not just waiting for joblessness.

In Ireland itself, meanwhile, many jobs are being worked by hands from beyond the boundaries of the Irish economy. And by this is meant both North and South.

There was a fascinating story in the New York Times last weekend that painted Ireland as a mini America, a country that is drawing in immigrants, has a growing population, yet is still young in contrast to the rest of what Donald Rumsfeld – a man who lost his jobs but hasn’t had to emigrate – once referred to as “old Europe.”

“No European Union country has a younger population: statistically, the Irish have been barely aging at all, with the median age staying close to 33. The country will remain young for decades, say the experts, and escape the graying’ fate of the rest of Europe,” the Times reported. “Further, demographers now predict that the population could rise to over five million in about a dozen years, and to six million within a generation. With a growing population in Northern Ireland, the island could match its largest population – more than eight million before the devastating 19th century famine that prompted waves of emigration – by 2032.”

It would seem that the “mass exodus” to Australia is not enough to put a dent in this overwhelming trend towards population growth.

Economies, however, are funny things. What if the Irish economy really did go into a nosedive? Who would run for the exit first, the Irish-born, or the immigrant arrivals?

And where would they go?

Some, of course, would return to their starting point and that, in immigrant terms, would mean primarily Poland, the Baltic States and West Africa.

The Irish-born? Well, apparently Australia.

But what about America? Bet on it!

If word gets out that there are jobs to be had in the 50 states then there will be Irish who will head west – this even if, unlike Canberra, Washington isn’t holding up a big placard saying, “Come on over, we need you.”

This is because America needs, even if legislators in Washington have a hard time in translating such need into written law.

So this is where we are at. Some Irish are leaving America, some are hanging on despite the lack of the kind of comprehensive immigration reform (thus far at any rate) that would allow them to stay.

Some of the Irish who forsook America for the old sod are staying there; some are going to Australia. And some, word on the street has it, are lately making their way back stateside.

Under such circumstances, predicting the future is indeed a risky business. In an ideal world there would seamless corridors for people to travel in search of work.

But the world isn’t that way. At the same time, the idea of Dublin and Washington signing a bilateral visa deal has been floated.

Such a deal would allow the Irish to more easily come to America to live and work, and more easily allow U.S. citizens to move to Ireland, that lately little melting pot on what was once considered Europe’s edge, but could now be viewed as a vibrant cusp between two great economic zones, North America and the European Union.

And then, of course, there is Australia, where Ned Kelly is now a national hero and the name Kelly will apparently get you a job in a jiffy.

Irish Australia’s gain is Irish America’s loss.

But only for the moment.