And now he faces headlines which say: Leonard supports England.
As former Labour leaders Jack McConnell and Gordon Brown know all too well, becoming embroiled in conversations around sporting allegiance rarely end positively.
Mr Leonard, of course, has told “the honest truth” and should be applauded for that. Asked who he would support in a football or rugby match between Scotland and England, the Yorkshire-born leader of Scottish Labour said it would be England.
Many have quickly denounced this as a “non-story” and First Minister Nicola Sturgeon tweeted to say “Man born in Yorkshire supporting England is not news”.
And she’s right. No-one really cares which football team the leader of Scottish Labour supports. However, as Mr Leonard is only too aware, the job he wants is not Labour leader, but First Minister of Scotland. Some will deny it’s a problem, but for a section of Scots the idea that their political leader doesn’t support Scotland in every way possible will be an issue.
Scotland vs England for the Grand Slam? Is Mr Leonard going to sing Swing Low Sweet Chariot at Murrayfield? Will he arrive bedecked in white-and-red for a vital World Cup qualifier?
Of course not. And, for many, sport is unimportant set alongside our many other challenges. But for others, sport is one of the few ways Scotland can express itself on the world stage as a country.
And the thought that our own First Minister might not be cheering along the national team will be tough for some to swallow when it comes to the crunch.
Nation states can take these issues seriously. In Australia, several politicians have been forced to resign as MPs after discovering that, unbeknown to them, they had dual citizenship.
Actor Arnold Schwarzenegger is a leading Republican politician in the US, who rose to become governor of California. However, because he was born in Austria, this US citizen is barred from taking the next logical step and making a bid for the White House. Whether Scotland is ready for an England fan in Bute House remains to be seen.