Really, this is unjustifiable. I used to believe the Democratic Party actually used “proportional representation” for its presidential nominating delegate allocation. But this is not even close.
“Realigned vote” is the shares after participants in candidate-supporting groups that were below 15% in any given precinct shift to their second choice. This is the only good part of the whole process. The “realignment advantage” is just an indicator of how much a candidate gains (or loses) at that stage: the realigned vote share divided by the initial vote share.
How you get from there to the final delegate allocation is clearly some sort of black magic. It goes by way of this weird phantom called “state delegate equivalents”.
And somehow out comes an allocation in which a candidate who started off in second place, even after realignment, not only comes in first in delegates but somehow is over-represented to about the same degree as the first place party in your average FPTP election. (Delegate advantage is the delegate share divided by the realigned vote share.)
This is not proportional representation. Whatever it is, it is no way to run a presidential nominating process.
See also a breakdown of available delegates by county and precinct. (The IDP link above has it even more detailed.)