A brilliant, knowledgeable, great debater, bombastic, erratic, arrogant, untruth teller - likely to implode?  The questions should be asked and not ignored.  The promises might not be implementable by him.   Think about it.

Poor manager
Not work well with others
Depending on the unsubtantiated promise of him devastating Obama in 3 debates (and perhaps fear of how well Romney will do)
Health - Overweight and needs to be healthy for the grueling Presidency, could die early
Work ethic? 
Bald faced, gross lying about Bain situation (or ignorance due to incompetence or lack of commitment to truth;
    he mouths the latter, but look at what he does.
High negatives 
Arrogance, brashness, off the cuff conclusions, oppositionalism
People waiting for him to implode
Effective Speaker, but drummed out by his members for his style and unpopularity
Brilliant, but erratic
Attacking, vitriolic


    6 Freddie Mac - Characterized self as "historian", then "consultant" but clearly influence peddler,
        claiming not a lobbyist (though he has $200,000 membership fee for clients and hooks people
        up)  See
    7 Lying, as above
       Adherence to marriage vows (forgive him, but watch out for expediency)
    7 Ethics violations - His claims don't ring true; 392-28 voted for ethics reprimand, all panels were
       equal in parties, but he claims it was only partisan

Past behavior - As indicator of future performance

    3 Cheating on wives
    6 Making enemies, if point made strongly  

How he works with other people 

     Pushed out as speaker
     Poor manager, lots of ideas but little carry through and management
          Undisciplined, erratic
     Scorched earth policy

Criticism of others:

Gingrich on "social engineering by the right" - a weak issue

Takes full credit where not due, stretching 

     Created balanced budget - Already set up before he was speaker, only there two of four years,
           Cost curve continued upward but economy raised revenues 20+ % (Duh!)
     Reformed welfare - One of Clinton's pledges in first election, others involved included Santorum
           and one other player who was critical
     Gained first majority for Repubs in years - Actually, similar to 2010, it was a reaction to Clinton
           and issues at the time, though he contributed to some degree
     Defeated the evil empire - Actually criticized as pathetic what Reagan did
     Reagan conservative - Criticized and insulted Reagan on floor of house and otherwise, but took
          on label for expediency

Gingrich Main Page

See links on that page to "scripts" for The Real World News w/
John Coldbear:
  King Of Bain
  Late January Killer
   Lobbying, Ethics