While some presidents, including those who occupied the White House for a full eight years, have struggled to be remembered at all 50 years after their deaths, Kennedy continues to loom large.
Many African presidents have tried to stay in power by rewriting their countries' constitutions to lose the limits on presidential terms.
Other signatories include two past presidents of the Faculty of Public Health and three former NHS regional directors of public health.
The three presidents, who have put their prestige alongside Mr Kabila's in the new phase of Congo's struggle for democracy, now find themselves in company where commercial interests are the only factor.
Presidents so deep into their second terms have, always, one eye on the horizon.
He told the Guardian: The 20 years between us meant nothing, because we had the heritage of Glasgow University – we were both presidents of the union.
Duda said on Monday he planned to leave Law and Justice, following a tradition of Polish presidents breaking formal ties with their parties to represent the entire nation.
New Hampshire is also a much bigger democratic exercise than Iowa, hence former New Hampshire governor John Sununu's famous, though not entirely accurate quip, that Iowa picks corn while New Hampshire picks presidents.
"We are determined to bring Ebola to an end and meet the deadline set by the … presidents for 15 April.
Related: Islam Karimov set to reprise presidential role as Uzbekistan heads to the polls This will be his third term under the current constitution, even though that same treaty limits presidents to two terms, an Organisation for Security and Cooperation in Europe observer mission noted in a report.
The factory was the toast of Uruguay - presidents and other dignitaries were regular visitors.
