Here former Massachusetts Governor Mitt Romney is seen next to Congresswoman (R-MN) Michele Bachman at the Iowa Republican Debates last month. Note his hand on her mid-back. This is a similar gesture to what is often seen between a parent and a child - going through doorways, across parking lots, etc. - in situations where some kind of protection or leadership is expected, etc. - but unlike the parent-child relationship, the emotions which drive this behavior are certainly not nurturing. Mitt Romney normally has pretty good body language sense & skill when compared to political office holders or candidates of any party or country .... but here he strikes out big time. This is seen as a patronizing and condescending signal to anyone who is watching who may be considering Romney, particularly if the voter is a woman. While it can be used sparingly once office is gained, to use it on stage with another candidate, especially by a man to a woman, in the setting of a debate - will lose you points every time.
CEO's, physicians, attorneys, managers and even sales people can be seen using this "False-Support Dominance Display" - to their significant detriment. It is always done by the higher ranking person to those in a more junior position (at least, from the point-of-view of the giver) or by those who are trying to engender a premature and thus false sense of familiarity.
It's as if the senior person feels the physical need to remind the subordinate - or them self - who's really in charge. It can be thought of as a variation on the Manipulator-Adaptor-Pacifier (MAP) - which, rather than performed on their own body part(s) - another is used as a surrogate; and while it may pacify the giver, it causes the receiver significant anxiety. In the setting of a televised debate, the audience "feels" this hand touch their backs'. Anyone who has ever been on the receiving end of this gesture knows the awkwardness that this generates. For those of you in power, whether you're the President, Prime Minister or a lower level manager, be very aware that this only serves to alienate those in whom you're trying to engender loyalty.