I think that since they do not believe it is the body and blood of Jesus Christ he was more or less just having a cracker with them.See also this PARODY, from www.scrappleface.com:
What's wrong with that?
Kerry Calls Pope's Abortion Stance 'Not Nuanced'(2004-03-29) -- The strict anti-abortion stance of Pope John Paul II is "tragically not nuanced," according to U.S. Democrat presidential candidate John Forbes Kerry, a practicing Roman Catholic.
"I pray for an America where rosary beads are sold in abortion clinic gift shops," said Mr. Kerry. "But I won't be a Catholic president, or even, as John F. Kennedy called himself, 'a president who happens to be Catholic'. I will be a president who happens to say he is Catholic but doesn't feel constrained by the black-and-white teachings of a church which is the bedrock of values, of sureness about who I am."
Mr. Kerry made the remarks as he left Sunday Mass at the Cathedral of Our Lady of Flexible Doctrine...
Primarily, it's an expression of a unity (communion means "union with") between the Catholic Church and this other Protestant faith that is not there. So it's a lie.
And by engaging in what a Catholic can only believe, as you said, is a "cracker," he is expressing for the world what is called "indifferentism," the idea that taking the True Sacrament in a Catholic Church and taking a symbolic communion in an AME church are equivalent. That what religion you profess and where you worship is not important.
SD