By Geoffrey Garrett and Simon Jackman
ILLEGAL immigration is a big issue in Australia and the US this election season.
But it is playing out quite differently on the two sides of the Pacific.
The Gillard Labor government has matched the hardline stance of the Coalition on the several thousand asylum-seekers who try to enter Australia by boat each year.
In the US run-up to November's congressional elections, Barack Obama's Democrats are going in the other direction.
They are stiffening their opposition to Republican efforts to get tough with the more than 10 million immigrants who entered the US illegally, mostly through the long and porous border with Mexico.
Our recent opinion polling with Yougov/Polimetrix during the first week of the Australian election campaign coupled with a similar poll in the US earlier this year suggests two reasons for this striking divergence.
Australians as a whole are more worried about immigration - both legal and illegal - than Americans. And with respect to partisan politics, Labor has less to gain and more to lose than the Democrats from taking a softer stance on illegal immigration.
Seventy-six per cent of our Australian respondents named asylum-seekers as "one of the most important problems" or at least "an important problem" facing the country, compared with 71 per cent of Americans.
On immigration more generally, 69 per cent of Australian respondents agreed that "right now, Australia is taking in too many immigrants", whereas 62 per cent of Americans thought similarly about their country.
Among the one-third of respondents who considered asylum-seekers "one of the most important issues facing Australia", the Coalition led Labor 47 per cent to 37 per cent.
For the two-fifths who considered the issue only "an important problem" (rather than one of the most important problems), the two parties ran neck and neck. Only among the 20 per cent of respondents who viewed asylum-seekers as "not all that important" did Labor lead the Coalition, albeit by a substantial 48-25 margin.
Kevin Rudd warned on the night of his ouster as prime minister that Labor was poised to move to the right on asylum-seekers, and the Gillard government has fulfilled his worst fears. But our polling shows that the electoral logic behind this decision is solid.
The partisan politics of illegal immigration are different in the US. Republicans held a 19-percentage-point advantage over Democrats among the 30 per cent of respondents who considered illegal immigration one of the most important problems - almost twice the Coalition's lead among the corresponding group in Australia.
But the Democrats had a 10-point lead over Republicans in the middle of the spectrum of American attitudes on illegal immigration, the 40 per cent of respondents calling it "an important problem".
And the Democrats led their opponents by a whopping 45 points among the one-quarter of respondents who didn't consider illegal immigration a major issue, almost twice as much as Labor's lead over the Coalition in the corresponding group in our Australian data.
These American partisan dynamics help explain why Obama and his Democrats opposed first Arizona's new law designed to identify and deport illegal immigrants and now the Republican push to rewrite the constitution so that the children of undocumented immigrants born in the US are no longer immediately granted citizenship.
Demography probably goes a long way to explaining these big differences in the politics of illegal immigration between Australia and the US.
In the US, most migrants in the country without legal visas are Latinos, joining what is America's largest ethnic group. Obama's Democrats are actively courting the Latino vote, largely sympathetic to the plight of illegal immigrants fleeing Mexico and other Latin American countries in search of a better life in Australia, by opposing Republican efforts to impose draconian measures on them.
In Australia, there is no similar ethnic constituency behind more compassion for asylum-seekers - even though many have fled dangerous war zones in Afghanistan and Sri Lanka - because of the very small numbers of legal migrants from these countries.
Obama's Democrats are hoping the Republicans will continue to shoot themselves in the foot when it comes to illegal immigration in the 2 1/2 months leading up to the congressional elections.
Asylum-seekers may not be a pivotal issue when Australia votes tomorrow because Labor has worked hard to neutralise what could be a vote-loser by adopting key elements of the Coalition's position.
But in both Australia and the US the governing centre-left parties are keenly aware of how the volatile issue of illegal immigration breaks among voters. This awareness explains how differently they are tackling the issue.
Geoffrey Garrett is chief executive of the United States Studies Centre at the University of Sydney and Simon Jackman is professor of political science at Stanford University