Answer: I believe . . . that his program would lead to the stagnation of the motive power that we need in this country to get progress.
Step-by-step explanation:
While President Kennedy was the president of the United States and Nixon was his vice president, there were some controversial issues which led to journalist asking them questions in order to get some details regarding some issues.
Based on the question, the evidence that is most relevant to Nixon's claim that his spending plans are superior to Kennedy's is that "I believe . that his program would lead to the stagnation of the motive power that we need in this country to get progress". Nixon attributed this to the fact that Kennedy's government expenditure was more than what he intends spending and would still move the country forward.