Barack Obama began his speech saying he's an American citizen and a citizen of the world (his first applause line) The McCain camp highlighted that phrase in its dismissal of Obama. Too, the dismissal spreads through the Meme-o-sphere.
But John McCain himself has used the phrase "Citizen of the World" in a speech on May 27th of this year at the University of Denver. [source]
There is such a thing as good international citizenship, and America must be a good citizen of the world—leading the way to address the danger of global warming and preserve our environment, strengthening existing international institutions and helping to build new ones, and engaging the world in a broad dialogue on the threat of violent extremists, who would, if they could, use weapons of mass destruction to attack us and our allies.
Many past Presidents (and the current one, too!) used "citizen of the world" in their remarks. Here's a collection of them....
Thomas Paine [source]
(Okay, so he's not a past President, but he is a prominent figure in the founding of our nation)
Speech of Thomas Paine, as Deputy in the National Convention of France, in Opposition to the Execution of the King.
"I was present at the time of the flight or abdication of Louis XVI., when he was taken and brought back. The proposal of restoring to him the supreme power struck me with amazement ; and although at that time I was not a citizen, yet as a citizen of the world, I employed all the efforts that depended on me to prevent it."
Calvin Coolidge [source]
Address at the Celebration of the 150th Anniversary of George Washington Taking Command of the Continental Army, Cambridge, Mass., July 3rd, 1925
Those men who have taken great parts in the world are commonly ranked by posterity according to their accomplishment while living, and the permanent worth of the monuments representing their achievements which remain after they are gone. By this standard I think we may regard George Washington as the first lay citizen of the world of all time.
Franklin D. Roosevelt [source]
Fireside Chat, December 24, 1943
Of course, as you all know, Mr. Churchill and I have happily met many times before, and we know and understand each other very well. Indeed, Mr. Churchill has become known and beloved by many millions of Americans, and the heartfelt prayers of all of us have been with this great citizen of the world in his recent serious illness.
Harry S. Truman [source]
Dedication of Home of FDR as a National Shrine, April 12, 1946
We stand in reverence at this hallowed spot consecrated to the memory of a great American who has become a great citizen of the world. We stand here in solemn tribute. All over the globe, plain people join with leaders and statesmen in recognition that it was largely because of him that civilization has survived. Only history can do him full justice.
Dwight D. Eisenhower [source]
Addressing the UN on Peaceful Uses of Atomic Energy, December 8th, 1953
I feel impelled to speak today in a language that in a sense is new--one which I, who have spent so much of my life in the military profession, would have preferred never to use.
That new language is the language of atomic warfare.
The atomic age has moved forward at such a pace that every citizen of the world should have some comprehension, at least in comparative terms, of the extent of this development of the utmost significance to every one of us. Clearly, if the peoples of the world are to conduct an intelligent search for peace, they must be armed with the significant facts of today's existence.
Dwight D. Eisenhower [source]
Dedicating the George C. Marshall Space Flight Center, September 8, 1960
Northern born and Southern schooled, all-American through military service, [General Marshall] ultimately became a citizen of the world. I, of course, knew him best during the prosecution of World War II. I found him immune to discouragement, relentless in carrying the war to the enemy, and unsparing of himself in his leadership of the great forces he directed. But so profound was his devotion to the constructive works of peace, so outspokenly was he their advocate as Secretary of State, that he later became the symbol of renewed hope for scores of millions of suffering people through his great plan for Europe that will forever bear his name. He became, in consequence, the only professional soldier ever to be honored with the Nobel Peace Prize.
John F. Kennedy [source]
Airport Rally, Roanoke VA. November 4, 1960
I come to Virginia and ask your help. Every citizen of this State is a citizen of the world. You do not need the reassurances of any man about our position in the world. You know it well. This State would not have survived unless the citizens of this State had had foresight, and you know as Virginians and as citizens of the United States that the United States has to be stronger, we have to do better.
John F. Kennedy [source]
Inaugural Address, January 20, 1961
And so, my fellow Americans: ask not what your country can do for you--ask what you can do for your country.
My fellow citizens of the world: ask not what America will do for you, but what together we can do for the freedom of man.
Finally, whether you are citizens of America or citizens of the world, ask of us here the same high standards of strength and sacrifice which we ask of you.
Lyndon B. Johnson [source]
Swearing in Ceremony of 3 men as Key Officials in Department of Defense, July 1, 1964
You men assembled here this morning come from many regions of our country-from New England, from the west coast, from metropolitan centers of the East, and from a small town in the Midwest. Each of you in your respective fields has established a most distinguished and impressive record. The country is fortunate to have your services in this critically important work of this period when the first purpose of America in the eyes of every citizen of the world is keeping the peace.
Lyndon B. Johnson [source]
Remarks at the University of Kentucky, February 22, 1965
Third, as an American citizen today, you are also a citizen of the world. Your cause is truly the cause of all mankind.
More LBJ: re: Eleanor Roosevelt, Shah of Iran
Richard M. Nixon [source]
Eulogy at Capitol during State Funeral of General Eisenhower, March 30, 1969
Some men are considered great because they lead great armies or they lead powerful nations: For 8 years now, Dwight Eisenhower has neither commanded an army nor led a nation. And, yet, he remained through his final days the world's most admired and respected man--truly, the first citizen of the world.
Richard M. Nixon [source]
Letter to Governors Urging Citizen Participation in Environmental Programs During Earth Week, April 12th, 1972
We have made a beginning in this new era of environmental enlightenment. But it is only a beginning. Every American and every citizen of the world must make a conscious and sustained effort if we are to succeed in protecting this earth which we all share."
Richard M. Nixon [source]
At Welcoming Ceremony in Bangkok, Thailand, July 28, 1969
I speak deeply from my heart when I say that to have this key will be a treasured possession--a treasured possession as President of the United States, but, more than that, as a citizen of the United States and as a citizen of the world who knows most of the great cities and who comes back to this city with a deep feeling of affection.
Jimmy Carter [source]
Farewell Address to the Nation, January 14th, 1981
For a few minutes now, I want to lay aside my role as leader of one nation, and speak to you as a fellow citizen of the world about three issues, three difficult issues: the threat of nuclear destruction, our stewardship of the physical resources of our planet, and the preeminence of the basic rights of human beings.
Ronald Reagan [source]
To the UN Special Assembly for Disarmament. June 17, 1982
Mr. Secretary-General, Mr. President, distinguished delegates, ladies and gentlemen:
I speak today as both a citizen of the United States and of the world. I come with the heartfelt wishes of my people for peace, bearing honest proposals and looking for genuine progress.
Later, in the speech, he continues
My people have sent me here today to speak for them as citizens of the world, which they truly are, for we Americans are drawn from every nationality represented in this chamber today. We understand that men and women of every race and creed can and must work together for peace. We stand ready to take the next steps down the road of cooperation through verifiable arms reduction.
George Herbert Walker Bush [source]
At the Presentation Ceremony for the National Medal of the Arts, November 17th, 1989
To Vladimir Horowitz for his extraordinary achievements and distinctive style as a pianist whose concerts brought pleasure to audiences everywhere and whose contributions to music made him a citizen of the world.
George Herbert Walker Bush [source]
Remarks at a Luncheon Hosted by the Venezuelan-American Chambers of Commerce in Caracas, Venezuela,
December 8th, 1990
I believe the day will soon come when every man and woman in the Americas is a citizen of the world's first completely democratic hemisphere, a hemisphere in which human rights are respected -- the strong are just; the weak, secure; and the rule of law prevails.
William J. Clinton [source]
Opening Ceremonies of Special Olympics, New Haven, Connecticut, July 1, 1995
President Kennedy once said that the rights of every man are diminished when the rights of one man are threatened. So tonight, I challenge all of you and every citizen of the world watching us to be an olympic champion for inclusion, a champion for equal rights, a champion for dignity, a champion for the triumph of the human spirit in all of us.
William J. Clinton [source]
Statement on the Death of Bella Abzug, March 31, 1998
Bella Abzug was a great American and a true citizen of the world. Her conscience, intellect, and political acumen made an immeasurable contribution to our public life. She raised her passionate and tireless voice demanding the best for women, for all Americans, and indeed, for people all around the world. She will be sorely missed.
William J. Clinton [source]
Remarks to the Community at Jackson Mann Elementary School in Allston, Massachusetts, February 2nd, 1999
There is no challenge larger than giving every child in this country a world-class education, for every child will be not only a citizen of the United States but a citizen of the world. If you look at these children up here, you won't be surprised to know that all over America we not only have the largest group of schoolchildren in history, it is the most racially, ethnically, religiously, culturally diverse group in history.
More WJ Clinton: Europe Summit in Istanbul, DNC Diner in San Diego, Presenting Congressional Medal to Father Hesburgh, Placido Domingo
George W. Bush [source]
An essential part of the foreign policy of this country is that we understand that freedom is not America's gift to the world, that freedom is the Almighty God's gift to each man and woman in this world. And as a responsible citizen of the world, we have the responsibility to help people live free lives. I believe freedom changes the world. I know free societies are peaceful societies
GWBush: re: Bono, Foreign Students in Vienna
My sources: Patrick Appel, Patrick Appel, Josh Marshall, and Lincoln in Duncan, and the American Presidency Project