KANSAS CITY, Mo. — In early September, Johnson County Sheriff Calvin Hayden spoke with a group of Johnson County conservatives known as the “Liberty People” about his efforts to investigate voter fraud. It was a freewheeling discussion that included calls for the elimination of all voting machines, unfounded insinuations that undocumented immigrants are voting, and promises that the sheriff was closing in on one of the biggest investigations of his career — despite no evidence of widespread fraud in Kansas’ most populous county. An hour in, an older woman piped up with an apparent call for act…