Final answer:
After the shift in tone, President Kennedy's tone became more inspiring and determined, highlighting his New Frontier vision of active citizenship and global leadership against the Communist threat.
Step-by-step explanation:
The bolder section above refers to a shift in tone that occurred in President Kennedy's era, signifying a transition from one perspective to another. After the shift in tone, President Kennedy's speeches and policies reflected a sense of urgency and ambition, often associated with the phrase 'New Frontier.'
This term is used to describe the vision Kennedy had for America, which involved tackling domestic and global challenges with vigor and innovation. Kennedy's tone after the shift was characterized by a blend of inspiration and determination, as he encouraged Americans to contribute to their nation and emphasized the willingness of the U.S. to take on significant responsibilities to contain the Communist threat.
This was evident in his inaugural address, which conveyed a message of active citizenship and global leadership, despite the future challenges that lay ahead in balancing internal and international affairs.