Already in 1677 there had been growing calls for a change in the order of succession, should
早在 1677 年，要求改变继承顺序的呼声就越来越高。
2015 English Cafe
Well, when a president dies, the order of succession now, for sure, is that the vice president becomes president, but people weren't quite sure at the time.
那么，当总统去世时，现在的继任顺序肯定是副总统成为总统，但当时人们不太确定。
英语百科
Order of succession
An order of succession is the sequence of those entitled to hold a high office such as head of state or an honour such as a title of nobility in the order in which they stand in line to it when it becomes vacated. This sequence may be regulated through descent or by statute.