  Decaying cold dark matter (CDM) has been considered as a mechanism to tackle
the tensions in the Hubble expansion rate and the clustering of matter.
However, polarization measurements of the cosmic microwave background (CMB)
severely constrain the fraction of dark matter decaying before recombination,
and lensing of the CMB anisotropies by large-scale structure set strong
constraints on dark matter decaying after recombination. Together, these
constraints make an explanation of the Hubble tension in terms of decaying dark
matter unlikely. In response to this situation, we investigate whether a dark
matter ensemble with CDM particles decaying into free streaming dark radiation
in different epochs can alleviate the problem. We find that it does not.
