How do those who hold to a view of open communion practice church discipline?

In the news recently is a discussion in the Roman Catholic Church about not giving Holy Communion to certain politicians who argue that 3rd trimester infants in utero are not to be acknowledged as having a human right to life comparable to adults. For those who are not Catholics, or are moderate Catholics, how should church discipline be practiced among the laity outside of Eucharistic bans? For example, during the Hitler era, most of the Lutherans in Germany did not refuse communion to those who belonged to the Nazi party. But were there other restrictions related to lay ecclesiastical service or church member identification?