1. If you have done joint work, be sure your personal statement says just what you contribution was, and encourage your department to get additional letters from the collaborators to that effect (but not as independent referees). Joint authorship is now the norm in much of social science and departments have to figure out a fair way of dealing with it.
2. As for significance, again in your personal statement, make clear what is the significance of the findings. No need to brag. Just tell it. From what I have seen, departments have definite ideas about significant work, and may well not tenure people whose work is significant but not by their lights.
3. You do need to publish in well regarded journals. But as important is the importance and seriousness of your work. Everyone can point to articles in the best journals, and wonder how they got through the review process.
4. If you are writing a letter of reference, and want to be influential, you must be fair, you cannot cast aspersions. Otherwise, you will be ignored unless someone wants to use your letter to do a hatchet job, a job that won't hold up on administrative review.
5. Whatever happens, living well is the best revenge. (This seems to come from George Herbert, but may well have been in common usage. Moreover, many point out that revenge is not a good idea, and you are better off looking forward or forgiving. In any case, living well will surely be good for you)
In other words, go off to another institution (whatever you may do legally about your tenure case), be productive, and realize that your success is what really counts. Don't worry about prestige--just ask whether the institution will allow you to do your work and support you. In the scholarly world, the connections you have with those people--throughout the country and the world--working in your area and who think well of your work is what counts--this is David Riesman and Christopher Jencks of 40+ years ago.
In other words, go off to another institution (whatever you may do legally about your tenure case), be productive, and realize that your success is what really counts. Don't worry about prestige--just ask whether the institution will allow you to do your work and support you. In the scholarly world, the connections you have with those people--throughout the country and the world--working in your area and who think well of your work is what counts--this is David Riesman and Christopher Jencks of 40+ years ago.
6. As for departments that deny tenure to an apparently worthy candidate--make sure all your future appointments and promotions are much stronger than that of the candidate you denied. Otherwise, you set yourself up for legal problems, and it is likely your provost will not be happy discovering that you have left the university open to liability.
My other blog, This Week's Find in Planning, and the new book out this Fall, has much more on tenure.