John F. Kennedy picked Adlai Stevenson, a famously eloquent political rival. Richard Nixon tapped Pat Moynihan, a maverick Democrat later to serve as a senator from New York. Bill Clinton's final choice was Richard Holbrooke, a forceful - some would say abrasive - geopolitical negotiator.
When it comes to picking an ambassador to the United Nations, US presidents have often opted for prominent and outspoken political officials. That's the kind of person needed to make US points heard in the cacophony that can be the UN - or so the thinking goes.
John Bolton may - or may not - be qualified to follow in these footsteps. That's a decision the Senate Foreign Relations Committee is weighing this week as it conducts confirmation hearings on Mr. Bolton.
To opponents, Bolton is a too- strident critic of the world's preeminent international organization. Defenders claim he's bracing - and he's right.
But one things seems sure: If approved, he would be far from the first US envoy to the UN to have the word "controversial" often cited in front of his name.
"It's one of the few international forums where we are one of many. We feel we need a distinctive, pointed voice there," says Thomas Carothers, director of the democracy and rule of law project at the Carnegie Endowment for International Peace.
On Monday, Bolton, who is currently the top State Department official for nonproliferation, told senators he would work to make the UN "more effective."
The UN has both strengths and weaknesses, Bolton said - citing as an example of its shortcomings the allegations of corruption in the UN's oversight of the Iraqi oil-for-food program. Perhaps seeking to soften his image somewhat, he told senators, "We see the UN as an important part of our democracy."
Sen. Richard Lugar (R) of Indiana, chairman of the Foreign Relations Committee, agreed with this sentiment, saying that the US "must be a leader in the effort to improve the United Nations, particularly in the area of accountability."
But Bolton appeared to face united opposition from the panel's eight Demo crats. They cited, among other things, his contention in 1994 that it wouldn't make a bit of difference if the UN building lost 10 stories, and his past description of UN peace enforcement and nation-building efforts as "chimerical."
In addition, Democrats have questioned Bolton's temperament, and charged that he may have tried to have two State Department analysts fired because he considered them too soft on Cuba.
"Quite frankly, I am surprised the nominee wants the job he's been nominated for, given the many negative things he has had to say about the UN," said Sen. Joseph Biden (D) of Delaware, ranking Democrat on the committee.
The political calculus
There are 10 Republicans and eight Democrats on the foreign relations panel. If the Democrats can lure one GOP Senator to cross lines, they can block Bolton's nomination from going forward with a tie.
At time of writing, however, it appeared that the most likely Republican defector, Sen. Lincoln Chafee of Rhode Island, was leaning toward approval of the nominee.
Senator Chafee said Monday that unless the confirmation hearing produced information to change his mind, he would vote "yes" on Bolton. He said that he had met with Secretary of State Condoleezza Rice and received assurances that Bolton would be following administration policy, not deciding it.
"Dr. Rice made it very clear that he will be working for her. And she made it clear that we are going to be more respectful of these international institutions than maybe we were in the past," said Chafee, according to wire reports.
Chafee was referring only to the recent past, but, over decades, the US has picked UN ambassadors who have addressed the UN in less-than-diplomatic tones.
Perhaps the most famous example was Stevenson's UN presentation of U-2 photos that proved the Soviet Union was establishing nuclear missile bases on Cuba. Stevenson was so tough he caused President Kennedy to observe, "He didn't think Adlai had it in him."
In fact, Stevenson was "one of the great communicators of his time," notes Robert Pfaltzgraff, an international security expert at Tufts University's Fletcher School in Medford, Mass.
Generally speaking, UN ambassadors are articulate, have made major contributions in some way to an administration's foreign policy, and are people who might conceivably be elevated to higher position some day, says Mr. Pfaltzgraff. "But most importantly, what they have in common is their ability to articulate the foreign policy of the administration, and they have the confidence of the president. That's the case with John Bolton," says Pfaltzgraff.
Other experts hold that Bolton might be further toward the controversy end of the scale than other past UN ambassadors.
Bolton's nomination is "both a challenge to the UN and a reflection of arrogance on the part of the US, or Bush," says Roberta Cohen, a former senior adviser at the UN who is now at the Brookings Institution.
But despite her specific objections to the Bolton nomination, Ms. Cohen notes that general trend of tough ambassadors holds true. "After all, the UN has about 191 states and even though the US is the most powerful, an ambassador who really stands out in that crowd and is not afraid to speak out can be an asset," says Cohen.