A little over a year ago, the leader of Sinn Fein, Mary Lou McDonald, looked like a shoo-in to become Ireland’s next prime minister (taoiseach). As the country heads to the polls on Friday, her chances look increasingly remote. Sinn Fein is now neck-and-neck with the two governing parties in the polls. And in her own constituency, McDonald is competing for a seat against one of the country’s most-unexpected candidates — a notorious crime boss. The World’s Europe correspondent Orla Barry reports.