How did hereditary succession differ from the earlier selection of caliphs through consultation and allegiance?

The selection of the first four caliphs, known as the Rashidun or "rightly guided" caliphs, was ideally based on the principles of shūrā (consultation), ijmāʿ (consensus), and bayʿah (allegiance), where the leader was chosen by his peers to act as a "first among equals."12

In contrast, Muʿāwiyah I introduced hereditary succession by securing an oath of allegiance to his son, Yazīd I, during his own lifetime. This shift disregarded the traditional election process and moved the caliphate toward a more secular, dynastic model of governance. While this change provided a pragmatic alternative to the often unreliable precedents for selection, it was widely viewed as a violation of the earlier consultative tradition and was considered illegitimate by many, leading critics to characterize the Umayyad rulers as kings (malik) rather than religious caliphs.312