There is certainly lobbying, but what the AAU has actually been doing is becoming *more* heavily reliant on those objective metrics to both look for potential new members or cut out the bottom schools. One critically important indicator is federal research funding (which was the subject of much of the debate about whether Nebraska would stay or go). Here were the figures for schools from 2010 (the last list that I can find):
http://chronicle.com/article/Extended-List-Research/65212
Interestingly, the University of Alabama at Birmingham is very clearly the top school outside of the AAU in terms of federal funding. That might seem a bit strange if you don't know about their graduate programs, but its medical school has a massive research facility (and medical research is where a disproportionate amount of federal funding goes to). #2 among non-AAU schools at the time was Boston University, who has since been invited. Only two other schools (Colorado State and Cincinnati) had over $200 million in federal research dollars in 2010 (albeit two others - Hawaii and the University of Illinois at Chicago, the latter of which houses the public medical school and research center for the state of Illinois - are very close). Utah, USF and Miami are the next ones on the list in terms of straight dollar amounts (although Miami would receive a *huge* benefit of having its figures "normalized" where figures are adjusted to account for schools that have smaller numbers of faculty members and students, so that's why I've noted previously that they're likely the next school in line to receive AAU membership).
This is where UConn needs to make up a lot of ground if it wants to truly compete for AAU membership (because believe me - virtually every halfway decent school has a plan to become an AAU member in the next 10 to 20 years, so having a plan in and of itself doesn't mean much). UAB, Colorado State, Cincinnati, Hawaii, UIC and Miami (with its normalized figures) are all schools that are very clearly in a tier above the rest of the competition on this critical (if not most important) metric. Putting aside any Big Ten thoughts, note that Cincinnati and USF are also clearly ahead of UConn on this metric, so that has to be taken into account for spots in places like the Big 12 or ACC, too.
Always remember that undergrad admissions don't really mean that much for AAU membership, so the fact that UConn is substantially more difficult to get into for undergrad compared to Cincinnati and USF doesn't matter because their medical research funding is substantially far ahead of UConn at this point. Looking at those figures should be a reality check when considering how incredibly stringent AAU has been in terms of adding members over the past 20 years. UConn would have to almost double its federal research funding to match what Cincinnati already has (and jump a whole slew of other schools like Kentucky, Wake Forest, LSU and even Princeton and Dartmouth in the process). UConn is also a large public school, so it's not going to get the benefit of adjustments for size in the same way that places like Miami, Wake Forest and Yeshiva would. We can say that anything is possible, but those are realistically extremely tough numbers to overcome in a short period of time. (It would likely take a generation of everything going correctly to make up that ground while also assuming that everyone that you're competing against stagnates.) Frankly, selling out 60,000 seats for football every game is probably an easier target by comparison.
