Maybe that's something new; a practicing Catholic will have to fill us in. When I was a Catholic, pre-Vatican II, I never saw such a thing. If you couldn't take communion, you stayed in your seat.
I believe this is what my PM does when he attends a Catholic church with his wife who is a catholic but not 100% sure as not really up on catholic practises.
The distribution of the Eucharist has become streamlined since the pre-Vatican II days. Leaving one's pew is optional, but given the relaxation of the rules about eating/drinking after midnight almost everyone goes up to the altar these days. Little children, who have not yet received their First Communion, walk up with their parents, with crossed arms, and receive a blessing instead of the wafer. Adults are welcome to do the same thing, and some do in the church where I attend.
I'm sure President Bush is grateful for every blessing that is offered to him. He needs buckets of grace to handle being with Nagin and Blanco for a whole day.
Archbishop Hughes is an institution in New Orleans, and I bet he has been instrumental in more reconstruction than Nagin has.