RA, I've always believed in calling people what they wish to be called
Matt, I've never been much on titles and you aren't one of my students or a junior officer working for me, so, I mostly go by John (or the JohnT handle).

While legitimacy is an extremely important dimension (and one of the 2 that were individually the most statistically significant) the essence of the research was that the whole (all 7 dimensions) were greater than the sum of the parts. Moreover, legitimacy is not an all or nothing dimension. It is made up of multiple variables each of which changes over time. I also break it down into 2 large components: system legitimacy and regime legitimacy. The US has system legitimacy because of the way our Constitution and form of government are perceived by the people. The Bush Administration has gone from relatively low regime legitimacy in January 2001 to extremely high legitmacy between the defeat of the Taliban and the defeat of Saddam to the low in the polls of today. (To complicate it further there is also legitimacy de jure and de facto) So, in the case of 2 opponents, both having legitimacy, id depends on (1) the other dimensions and (2) the relative legitimacy of the regime, system, de jure, and de facto at that time.

Cheers

JohnT