“Senator Romney’s commitment to our Constitution makes him a worthy successor to the senators who inspired my father to write ‘Profiles in Courage,’ ” Kennedy’s daughter, Caroline Kennedy, said in a statement from the JFK Library Foundation. “He reminds us that our Democracy depends on the courage, conscience and character of our elected officials.”

Romney, 74, said he is inspired by the memory of his late father, George Romney, an automotive executive and governor of Michigan.

“When I think of courage, I think of my Dad,” said the Utah Republican, who is also the former governor of Massachusetts. “He did what was right regardless of consequence. I aspire to his example, though I have failed from time to time. We must subordinate our political fortunes to the causes of freedom, equal opportunity and truth, particularly as they are under assault here and abroad.”