  We study certain N=1 preserving deformations of four-dimensional N=2
superconformal field theories (SCFTs) with non-abelian flavor symmetry. The
deformation is described by adding an N=1 chiral multiplet transforming in the
adjoint representation of the flavor symmetry with a superpotential coupling,
and giving a nilpotent vacuum expectation value to the chiral multiplet which
breaks the flavor symmetry. This triggers a renormalization group flow to an
infrared SCFT. Remarkably, we find classes of theories flow to enhanced N=2
supersymmetric fixed points in the infrared under the deformation. They include
generalized Argyres-Douglas theories and rank-one SCFTs with non-abelian flavor
symmetries. Most notably, we find renormalization group flows from the deformed
conformal SQCDs to the $(A_1, A_n)$ Argyres-Douglas theories. From these
"Lagrangian descriptions," we compute the full superconformal indices of the
$(A_1, A_n)$ theories and find agreements with the previous results.
Furthermore, we study the cases, including the $T_N$ and $R_{0,N}$ theories of
class $\mathcal{S}$ and some of rank-one SCFTs, where the deformation gives
genuine N=1 fixed points.
