  It has been observed that an automatic alignment without decoupling is
predicted at tree-level in a Two-Higgs Doublet Model (2HDM) with extended
supersymmetry in the gauge and Higgs sectors. Moreover, it was found that
radiative corrections preserve this alignment to a very good precision. We show
that it is the non-abelian global $SU(2)_R$ R-symmetry that is at the origin of
this alignment. This differs from previously considered Higgs family symmetries
as it is present only in the quartic part of the Higgs potential. It can not be
imposed to the quadratic part which has to be generated by $N=1$ supersymmetry
breaking sectors. This absence of symmetry does not spoil alignment at the
minimimum of the potential. We show how the (small) misalignment induced by
higher order corrections can be described as the appearance of non-singlet
representations of $SU(2)_R$ in the quartic potential.
