Caucuses tend to amplify the minority in a given state: I believe that in this case, IA was in fact Sanders' state to lose and that the caucus there actually benefited Clinton (independent of any potential delegate allocation issues that also may have helped).
Um... what? Why would caucuses be inherently likely to amplify the minority? The types of people who are in the minority vary state to state.
Caucuses amplify the sorts of people who can afford to take a day off to spend all day at a caucus. The types of people who can afford to do that have been disproportionately favorable to Sanders (despite Clinton overall doing better with wealthier voters, most of the voters disenfranchised by caucuses are poor, racial minorities -- her real base and best demographic.)
Are you saying that you think in white heavy states you think racial minorities are
over represented by caucuses? Where do you get that idea?