Effects of the coupling to $^{6}\mathrm{\ensuremath{\alpha}}$+d nonresonant continuum states on polarized $^{6}\mathrm{Li}$ scattering at ${\mathit{E}}_{\mathrm{lab}}$\ensuremath{\simeq}20--100 MeV are investigated in the framework of the continuum-discretized coupled-channels (CDCC) method which takes into account the resonant and nonresonant \ensuremath{\alpha}-d breakup states of $^{6}\mathrm{Li}$. A convergence of the calculated analyzing powers of $^{6}\mathrm{Li}$ elastic scattering against the size and the discretization of the breakup continuum is examined. The resulting model space of the breakup states consists of the \ensuremath{\alpha}-d S-wave (l=0), P-wave (l=1), and D-wave (l=2) states up to the \ensuremath{\alpha}-d relative momentum of k=1.2 ${\mathrm{fm}}^{\mathrm{\ensuremath{-}}1}$. The results of the CDCC calculation show that the effects of the nonresonant breakup states are quite as significant on the analyzing powers as those of the resonant breakup states.