You read again. The overall registered voter turnout in 2016 was 64% in a presidential election year. What they're saying is half the number of those R voters came back and almost all of the D voters did. Even if all came back from both parties, it's nowhere near 100% for either.
Special election turnout is key. Dems got most of the number that got smashed last November to come back and only won by 1.5%. That only happened because almost 23K were write-ins, which would have been enough to cover the loss by a few hundred.
Keep screaming voter fraud and looking like a clown.
Overall registered turnout includes Indies, which vote at lesser percentages than party affiliated, which tend to be around 80% for Dems, 90% for Reps.
That would yield about a 73% turnout for Dems, 45% for Reps in the special. Anything above 25% in a special is an amazing turnout, I've only seen approaching 50% in very small local elections, and only one time. Never ever anything statewide.
70+% turnout for the Dems in a special has never been achieved anywhere, anytime for any election that I've ever heard of, certainly not statewide.