Three things come to mind here.  The first:

1)  There seems to be a view of the Eucharist proposed by some (including perhaps the present pope) that verges on magical thinking:  the notion that the Eucharist is some sort of spiritual vitamin that perks us up--the corollary being that if you don't receive Communion you run the risk of becoming spiritually malnourished.  So it follows that it can only be 'merciful' to open Communion up to the divorced-and-remarried, and indeed (following the logic further) to all comers.

While we can't expect to hammer out a complete Eucharistic theology in a combox, I'd suggest this view is in many ways deficient.  An alternative is one in which the Eucharist encourages us to repent of our sins and reform our lives.  Instead of insisting that the Eucharist be supplied to us, we should move towards personal holiness and thus be bring ourselves closer to the sacrament.