Keep on winning either on the pitch or the ballot box and they get to keep their job and bask in all the glory that repeated success brings. However, once they hit a losing streak, their days are numbered.
Going from hero to zero is not a pleasant experience, as the former Labour leader Eamon Gilmore learned last year when his party’s vote collapsed in the local and European Parliament elections.
At the time, Gilmore did the honourable thing, took responsibility for those disastrous results and fell on his sword.
Now, though, he has plucked that sword from his political bosom to take a swipe at his successor, Joan Burton.
His memoir, Inside The Room — The Untold Story of Ireland’s Crisis Government, is promoted as a revealing account of how the coalition handled the recession and put the country back on the road to economic recovery.
Yet its real focus is to suggest that he fell foul of forces within the Labour Party working against him.
Like too many Irish politicians, Eamon Gilmore likes to have it both ways. As his memoir clearly indicates, he wants to go down in history as the most successful leader ever of the Irish Labour Party.
There is some justification for that. In the 2011 general election, Labour took 37 Dáil seats, becoming the second largest party for the first time ever. There was even talk in political circles of Mr Gilmore becoming taoiseach.
Yet, by the same token, he is also the party’s biggest political failure, managing to snatch defeat from the jaws of victory. Almost every poll taken since 2012 has shown Labour to be losing support until finally collapsing last year.
That all happened on Mr Gilmore’s watch.
There is something unseemly and mean spirited about a former party leader dumping on his successor as she attempts to get Labour back on track and recover lost ground in next spring’s general election.
“I think this book will be a help to the Labour Party and to Joan Burton,” Mr Gilmore said yesterday, indicating either a twisted sense of humour or political naivety that belies his long experience both in government and opposition.
Mr Gilmore knows the effect that words can have. Speaking yesterday on RTÉ radio he revealed that it was he who had come up with the 2011 election slogan “Labour’s way or Frankfurt’s way” — a phrase meant to persuade voters that the economic pain would be less with a strong Labour vote.
The slogan came back to haunt him in little over a year when Labour was forced to capitulate on election promises.
His memoir, in so far as it is a kick in the teeth to Joan Burton, may do the same.
As Enoch Powell once declared: “All political lives, unless they are cut off in midstream at a happy juncture, end in failure.”
That does not mean they must end in brooding resentment.
Mr Gilmore should have left the sword where it was.