What is the meaning of the word sterner in line 20 of this speech Anthony?

In the context of Anthony's speech, the Word "sterner" likely refers to a more serious, strict, or resolute attitude or approach. It suggests a shift towards a firmer stance on the issues being discussed, emphasizing the need for greater intensity or urgency in addressing the challenges at hand. This choice of Word conveys a call for strength and determination in pursuing justice or equality.