What leads to contentious tenure cases and can they be avoided? After hearing about an incredibly contentious tenure case at my alma mater and several other contentious ones, I'm curious to hear how such issues come to be. Some issues that seem to be at play: personal animosity between faculty, dispute about the merits of the candidate's research, scarcity of resources and discrimination based on gender, sexuality, religion and other aspects of identity. Some of these are legitimate, while others are clearly not. For those curious as to how nasty things can get, I recommend reading here. The account is both appalling and fascinating.

Do faculty see these issues coming? Are there tell-tale signs they might miss? One person I talked to was quite surprised both by the animosity one fellow faculty member had towards him and by the degree of influence this brought to bare on his tenure case.

Once such issues have been identified, how can the candidate defend against them? At what point should he/she be prepared to defend against them? From the other side, what processes exist to prevent such biases from influencing the process? Are they functional, and to what degree? Are there better practices that could be implemented to avoid such discontent?
One source of problems is a lack of communication over what are the expectations for the tenure candidate to meet before becoming "eligible" to receive tenure. But a substantial amount of the issues can lie with either someone in the decision-making chain, or the candidate himself or herself. In the latter case, this makes a tendentious situation inevitable.

For instance, there is the rather notorious case of James Sherley at MIT, who alleged multiple issues, including racism, and claimed that he believed his papers from his previous institution would "count" toward his tenure case. (Meanwhile, at MIT, his publication list in five years amounted to a total of six publications, three of which I believe were editorials.) He went on to hold a hunger strike to protest. 

So I think that there really isn't a way to prevent things from becoming contentious unless everything is made "open": criteria are specified in advance, and everybody participating can follow along the entire process. (That is, the candidate can attend the meetings where the tenure case is being discussed.) However, I suspect this is unlikely to occur.