You just needed to follow the public debate over the past two weeks to know that the guy remains a magnet for vitriol and conflict, not someone respected enough to be the world's top diplomat.
The public debate may have been decisive for Turnbull.
Until the debate went public, there had been a conventional wisdom that despite his failings, it would be unthinkable, even "unpatriotic" for Turnbull not to nominate Rudd.
It has reportedly been the view of Foreign Affairs Minister Julie Bishop and so Turnbull's decision was not without some cost. But it was going to be a costly decision politically either way.
The pro-Tony Abbott faction in his Government would not sit by quietly if Turnbull had given the nod to a clearly unsuitable opposing Prime Minister when he could not find a place for Abbott within his newly formed cabinet.
Assuming that merit played at least a tiny part in the selection process, Rudd stood no chance of winning the job.
But that does not mean a nomination by Australia would have had no effect on Helen Clark's. It would have been unwelcome competition that could be used by those most threatened by Clark.
One of New Zealand's strongest arguments against the "Eastern Europe's turn" is the fact that the region cannot get behind a single candidate.
Likewise the fact that two women from Latin American countries, Susanna Malcorra from Argentina and Christiana Figueres from Cost Rica, has weakened the other's candidacy.
Having to compete against a neighbor, albeit a completely unsuitable one, would certainly not have helped Clark.
She needs all the help she can get to rise from the mid-pack to the final three or four in next week's ballot.
Turnbull said in his press conference that the Government will consider in due course whether it supports Helen Clark.
That may be a step too far for Australian nationalists.
But really the test should be a simple one for Turnbull. He has set a high standard of suitability. He should apply the same test to Clark and the answer should be obvious.
