Barack Obama's bid to become the first black American president could have taken a blow with the revelation that his aunt was an illegal immigrant in the US.

News about 56 year old Zeituni Onyango just three days before election is a chance for Republican presidential candidate John McCain to generate some last-minute negative headlines about Obama.

But Obama has denied having any knowledge about his aunt living in the US illegally, and said laws covering the case should be adhered to. A statement given to the Associated Press (AP) by Obama's campaign said: "Senator Obama has no knowledge of her status but obviously believes that any and all appropriate laws be followed."

Traveling with Obama in Nevada, Democrat¹ campaign strategist David Axelrod declined to elaborate on the statement, but said: "I think people are suspicious about stories that surface in the last 72 hours of a national campaign."

AP found that Onyango, who is mentioned in Obama's personal memoir², had been instructed to leave the country four years ago by an immigration judge who rejected her request for asylum³ from her native Kenya. But the half-sister of Obama's late father is living in public housing in Boston.

She has even donated to Obama's campaign, with five small gifts totalling $260. Those donations may turn out to be illegal because she is not a US citizen.

Illegal immigration is a political minefield in US politics, and the story could be a vote-losing headache for Obama. Her refusal to leave the country does not make her unusual in the US - there are an estimated 10 million "illegals" - but the issue is hot especially because Obama and McCain both are trying to woo white working-class voters. Illegal immigrants are often accused of taking jobs from legal residents.

On Saturday, McCain was nudging into a slight lead in one element of a three-day tracking poll by respected pollster John Zogby. The overall survey, though, still gave victory to Obama by five points.

Obama will hold a rally in Chicago after the polls close on Tuesday night, and up to 1 million people could flood the city's streets. All police leave has been cancelled and off-duty firefighters have been told to keep their kit⁴ ready at home. The unspoken concern among some officials is that a surprise Obama loss - especially with most polls predicting a win for him - could lead to civil unrest.

Detroit and Los Angeles were also deploying⁵ extra police out of concern for heightened emotions raised by this election.

The Zogby poll found McCain's support was increasing among independents and working-class voters. It could prove that McCain's recent tactic⁶ of pushing blue-collar issues, symbolized⁷ by his adoption⁸ of "Joe the Plumber⁹" as a campaign totem, is working. But virtually every other national poll suggests Obama has a healthy lead.

Questions:

1. What was the name of Barack Obama’s aunt?

2. Why is the issue hot?

3. Where and when will Obama hold a rally?

Answers:

1. Zeituni Onyango.

2. Because Obama and McCain both are trying to woo white working-class voters. Illegal immigrants are often accused of taking jobs from legal residents.

3. In Chicago after the polls close on Tuesday nightntries.