I have had dealings with Martin McGuinness
, a former Irish Republican Army (IRA) commander, for almost 20 years. I know his background, I know the stories they share about him.
Yet I find him more human, easier to deal with than his colleague Gerry Adams. Even during the stressful early days of the peace process, McGuinness never lost his sense of humour or easy way with the media.
The decision by Sinn Fein to run him as a candidate in the Irish presidential election is opportunistic but not surprising.
Senator David Norris was the early favourite. Smart, personable and openly gay he is well regarded in many parts of Ireland but errors of judgement were highlighted and he dropped out of the race.
Once Ireland's biggest party, Fianna Fail has a formidable political machine across Ireland. It regards itself as the natural party of government but is still recovering after the drubbing it took from the voters in the general election this year.
Producing a winning candidate in the presidential election would have been a step in the right direction - but its hamfisted courting of Irish broadcasting legend Gay Byrne and his ultimate rejection of their advances means they will not even field a candidate.
Dogged by IRA past
Sensing an opportunity - and Sinn Fein have never been poor at that - the Republicans decided they needed a standard bearer and McGuinness would be it.
The party has grown in support in the Republic of Ireland in recent years and the number of TDs (members of the Irish parliament) and senators stands at 17 - McGuinness as the Deputy First Minister in Northern Ireland is an assured political operator.
He stands as the anti-establishment candidate and will undoubtedly pick up protest votes in a country still angry at the EU-IMF bailout and the harsh austerity measures imposed to reach tough financial targets.
But he is a former commander in the IRA - in charge of one of the most lethal organisations during it's time of opposition to British rule in the northeast corner of the island of Ireland. And so, in the way Kurt Waldheim's presidency in Austria was dogged by his links to the Nazi Party – McGuinness will be asked what did he know of what was really going on.
The IRA killed 644 civilians during it's self styled "long war" against British rule. It killed children in its attacks. It practiced kidnapping and extortion and acts of torture. And it carried out its own style of justice on the streets of Northern Ireland including beatings, shootings and the "knee-capping" of people accused of breaching the rules imposed by the group itself.
For much of this period, McGuinness was thought to be a member of the IRA's ruling "Army Council". Writer Fintan O'Toole argues in a recent edition of The Irish Times that "legally and morally, this makes him responsible".
McGuinness has dismissed what he called "a media fixation" on his time on the IRA and says he will not apologise for the role he played.
The role of president in Ireland is mainly ceremonial – but it would be hugely symbolic if a man regarded by some as a former "terrorist" and by others as a reason the peace process developed in Northern Ireland gets the top job.
His arrival into this new battle will undoubtedly concentrate the minds of the other parties, not least because he is already topping some opinion polls.
In this episode of Talk to Jazeera, which first aired in 2007, McGuinness spoke to Al Jazeera's Alan Fisher.
Watch part two of this episode of Talk to Jazeera here.