I have been reluctant to engage in speculation over potential Secretary of State candidates because the discussion therein is fraught with far too many nuances to outline succinctly without walking ourselves through a mine-field almost too complex to digest.
Suffice to say, anyone who has followed politics for any substantive amount of time knows the inherent issue with an operational entity, The U.S. State Department, whose entire mission has been at the epicenter of ctrl-left globalist advocacy.

One small example would be the Rivkin Project. Imagine how challenging it would be to take an organizational model, built over decades, and appoint a leader whose diplomatic mission would be to implement/construct policy entirely antithetical to the objectives of the participants within the organization?
Think about it.

A shorter consideration would be to accept: A true “America First” diplomatic outlook is an existential threat to the preferred mission statement of the U.S. State Department.
Initially that might sound overly dramatic, but when you boil it down to the underlying ideological denominator –and really look at the past four decades– the description is not inaccurate.
That said, we have no insider information AT ALL, and what follows is purely a researched opinion (in the same vein as all prior behavioral research outlines) into some of the considerations for any Trump nominee.
The safest person for Donald Trump would be Rudy Giuliani. His perspective, outlook and trust factor is in alignment. Rudy is also at the top of the list for many Trump supporters, including me.  I like the guy.  Giuliani’s got just the right blend of piss and vinegar to be capable of dealing with the nest of vipers that awaits – he’s a former federal prosecutor who knows how to investigate and accumulate evidence of systemic corruption – and his loyalty toward the objectives of the incoming Trump administration is without question.
But there’s a problem that most have overlooked. Rudy Giuliani has a visible issue with excessive alcohol use.
Oh, sure there are other issues that have been rightly mentioned in regard to Giuliani’s business interests, but in my opinion those issues are far less important in this consideration. When you add in President-elect Trump’s severe aversion to alcohol dependency, and consider the intensely personal example of Frederick “Fred” Jr. (1938–81), well, if you’ve paid attention you know the scope of the issue.
Anyone who has ever been in a position of executive organizational leadership will tell you how challenging it is to overcome a similar problem once it surfaces. Painful decisions are caused by the need to contrast best-interest logic over emotion; and the most likely, albeit agonizing, outcome is a necessary removal of the individual regardless of relationship. Effective leaders cannot allow the organizational goals to be hampered by excessive loyalty toward an individual whose own decisions are creating the toxicity.
Perhaps addressing this issue is why Giuliani has been mostly invisible over the past two weeks. Perhaps, just perhaps, he too is trying to address the matter. [That’s definitely my own personal hunch] Which brings up the issue of likelihood of success etc. An unknown variable.
Think about all of inherent issues therein. Think about the personal, emotional and also the operationally logical.
If not Rudy, then who?
If you go back to rethinking the larger State Dept. challenge -deeply- does it really matter? The nominee, any nominee, will essentially be in charge of a U.S. Department that is comprised almost exclusively of Kerry/Clinton/Obama/Bush/UniParty/GOPe big “G” Globalists.
These entities see themselves as a complete and separate structure of government. They also function as a complete and separate ideological structure of government:

When you accept the scope of the challenge, and recognize it is almost impossible to change the participants therein; and accept these career embeds will work earnestly and diligently to undermine the structure of a Trump administration at every opportunity; perhaps the best outcome is to not to try and change their system, but rather manage/control the amount of damage they can do toward the larger administration objectives.
It is going to take some outside-of-the-box thinking to find the patriot who can deal with the scope and severity of the opposition.
Cut the rotting vehicle down to the frame and cut out all the rust is going to be an epic battle with ZERO Washington DC supporters as you endeavor the restoration.  Actually, the leadership within both wings of the UniParty can predictably be guaranteed to impede any such effort:

“There is nothing more difficult to plan, more doubtful of success, nor more dangerous to manage than the creation of a new order of things. … Whenever his enemies have occasion to attack the innovator they do so with the passion of partisans, while the others defend him sluggishly so that the innovator and his party alike are vulnerable.”
~ Niccolo Machiavelli

So, is it better to go with the bondo, paint and polish approach, thereby avoiding the necessary, and predictably explosive, confrontation while you tackle the more important domestic economic and security issues?
Two different approaches.
Now, who might be the best candidate to overcome those hurdles?  There’s a reason the list is expanding…