  The changeover from first-order to second-order phase transitions in q-state
Potts models is obtained at q_c=2 in spatial dimension d=3 and essentially at
q_c=4 in d=2, using a physically intuited simple adaptation of the
Migdal-Kadanoff renormalization-group transformation. This simple procedure
yields the latent heats at the first-order phase transitions. In both d=2 and
3, the calculated phase transition temperatures, respectively compared with the
exact self-duality and Monte Carlo results, are dramatically improved.
