Looking at Senate Primary Turnout so far..

[MarkD]

I'm predicting about this much turnout for MO-Sen this year, August 2: around 990,000 votes in total; about 441,500 in the Dem primary and about 544,500 in the GOP primary (and about 4,000 in Libertarian and Constitution Party combined). There doesn't appear to be any referendum on the ballot this August that will boost turnout, like in 2004 (same-sex marriage) or in 2018 (right-to-work).