We show that describing the screened electrostatic interactions in a periodic stack of rigid parallel identical charged platelike colloids within a local density functional theory approach generically leads to a swelling behavior. Within the same framework, we find that the effective potential between a pair of such plates immersed in an electrolyte is repulsive at all distances. This general result is in contradiction with a theory put forward by Sogami, Shinohara, and Smalley, that we criticize and thoroughly reconsider to show how the two approaches can be reconciled.