Yes, but does he think they believe, as he insists, that his IRA career ended more than 30 years ago? "Does who believe me?" he said. The majority of people. Again, a shrug. "I don't think the majority of people - to be quite honest - care," he said. "I think they see me as someone who was at one stage of my life in the IRA, but they see me in the round, as someone who was able to make peace."
The perception that McGuinness is persisting in a lie is troubling for a great many people in Ireland, many of whom see his arrival in their presidential contest as an unwelcome cross-border intrusion.
But more than a few are prepared to accept his stance, regarding it as something he has to maintain out of political or legal necessity.
This approach of putting the pragmatic before the dogmatic has been apparent for some years in Northern Ireland, where the Sinn Fein leader is credited with successfully sharing power with Paisley. McGuinness was mentioned in last year's report into the Bloody Sunday shootings in his home city of Derry in 1972, which concluded that McGuinness probably had a machine gun on that day but did not allege he opened fire.
When Paisley's son, a Westminster MP, was asked if this made him imagine McGuinness with a machine gun, he replied drily: "I never imagined him without it."
Nonetheless, loyalists have been amicably governing alongside Sinn Fein. In this election the republicans are attempting to insert themselves into the political mainstream in the south, building on recent advances to the alarm of conventional parties.
As part of this effort McGuinness is deploying language not usually associated with the republican movement: he does not denounce all IRA killings, but he does distance himself from some of them. Last week, for example, he described the 1987 Poppy Day bombing in Enniskillen, when the IRA killed 11 Protestant civilians, as "atrocious". He said he was ashamed of the republicans who carried it out.
Because they had killed civilians? "Absolutely."
Can he win the election? It's what might be called a long shot, for he is third favourite of seven candidates. Sinn Fein has put him forward because a yawning gap opened up in the political market with the implosion of Fianna Fail this year.
While McGuinness is the biggest celebrity among those standing, his selling points are not his republican credentials but rather his personality and the fact that in the south Sinn Fein is determinedly anti-establishment.
Many Irish voters remain angry with a political system that they blame for ruining the country's economy.
McGuinness will find most of his votes among the unemployed, the poorly paid and the debt-ridden.
His hope is presumably that in the next few weeks much of the heat will go out of the debate on his IRA role, leaving him well-positioned to harvest the votes of the alienated when they go to the polls on October 27.
- Independent