Resonant Two-body D Decays

The contribution of a $K^*(1430)$ $0^+$ resonance to $D^0\to K^-\pi^+$ is calculated by applying the soft pion theorem, and is found to be about 20% of the measured amplitude and to be larger than the $\Delta I=3/2$ component of this amplitude. We estimate a 50% contribution to the total amplitude from a higher $K^*(1950)$ resonance. This implies large deviations from factorization in $D$ decay amplitudes, and an enhancement of $D^0-\bar D^0$ mixing due to SU(3) breaking.