Scourge of migrants known as 'America's toughest sheriff' faces day of reckoning

Joe Arpaio is facing a civil rights lawsuit over anti-immigration policies in Arizona (Getty Images)

It'll be business as usual today at the prison complex just outside Phoenix, Arizona, where Joe Arpaio has spent two decades attempting to do justice to his self-proclaimed nickname: "America's Toughest Sheriff."

At 2.30pm, the a rotund, bespectacled 80-year-old police chief, known as "Sheriff Joe", will hold a press conference to unveil what a spokesman promises will be "breathtaking" new evidence that Barack Obama was born outside the US, and is therefore ineligible to be President.

In any sane universe, a group of elderly, white, right-wing men trying to advance this long-debunked and – some might say – racially-motivated conspiracy theory would be either ignored or treated with contempt. But Mr Arpaio will surely get the limelight today, just as he has done throughout his tenure as Sheriff of Maricopa County, the portion of Arizona which includes Phoenix, where he was first elected in 1992, and where he faces a re-election battle this November.

Not much publicity is bad publicity for "Sheriff Joe," who has risen from small-town obscurity to become a staple of national conversation on the back of controversial PR stunts – whether they involve Barack Obama's birth certificate or, to pluck another example from Mr Arpaio's CV, a policy of forcing prisoners to wear pink underpants.

It is his stance on the thorny issue of illegal immigration which has earned him perhaps the greatest notoriety, however. In recent years, his department has begun conducting high-profile "sweeps" of its territory, in which just under 30 per cent of citizens are Hispanic, arresting tens of thousands of suspected "illegals" and then handing them over to authorities for potential deportation. On Thursday, this policy is due to land Mr Arpaio in Phoenix's Federal District Court. There, he will face a class-action civil rights lawsuit filed by several innocent victims of the "sweeps".

The plaintiffs include Manuel de Jesus Ortega Melendres, a Mexican citizen who has a valid visa allowing him to be in the US, but was arrested, handcuffed and held for hours by Mr Arpaio's officers in 2007 without being read his rights. They also include two US citizens, of Hispanic appearance, who were held at gunpoint during another "sweep".

To critics, Mr Arpaio represents a case-study in the flaws inherent in the direct election of sheriffs. Yet for all the kerfuffle, he has already received nearly $1m in campaign donations this year. His nearest rival for November's ballot has meanwhile raised a paltry $50,000. Despite, or perhaps because of his gift for controversy, America's toughest sheriff looks set to keep on winning elections.