No matter who ultimately wins in Iowa, and whatever shakes out with the app fail, the "meh" turnout vs 2008/2016 is the headline. It suggests less urgency and more contentment with Trump among more white voters than I think the "heartland"-obsessed Democrats acknowledge. 
There is a passionate core of progressives, regular order white Dem liberals and centrists & Never Trump Republicans who abhor Trump (I met a lot of them in Des Moines)! But these results suggest Dems; who have no Obama, had better nominate someone who strongly appeals to POC.
That's how Carter won, that's how Bill Clinton won, and that's how Barack Obama won (by 10 and 5 million votes) despite none of them ever topping 46% of white voters. IOW much love to Iowa and NH, but keep your eyes on NV, SC and the diverse Super Tuesday states.
If turnout is lackluster in THOSE states too? Then Dems need to start freaking out. If you consider Trump's approval ratings by race and note that Iowa is a largely rural state and that Obama was a once a generation candidate, it's not time to panic (yet).
