Now here is the tricky part. AnM can do this because:
a) The Governor of Texas is an Aggie, and
b) He is distracted by running for President, and
c) There are at least three in-state schools that could replace AnM.
In fact the only thing for the legislature to decide is do they add SMU (Dallas) or Houston. Of course the Big 12 could offer Houston, SMU, and TCU and get back to a 12 team conference; or bring in UTEP, BYU, Air Force, and Tulsa as well and go 16 teams.
That is important because the States of Oklahoma and Virginia cannot simply turn to another in-state school if Chokelahomo and Virginia Tech bolt for the SEC. That leaves Okie St and Virginia all alone. The State Legislators in those States could flex their muscle and force both to stay put. If Chokelahomo stays then the Big 12 will keep Missouri by any means necessary (although I just don't believe we want Missouri).
No VT and no Chokelahomo would mean Slive looks to NC but here again the State Legislators could hold NCST or NC in place. Now we can't roll with 13 so that means that we would have to offer Clampsun, or FSU, or GT.
To block any expansion you have to have four votes. South Carolina, Georgia, and Florida are naturally against this. However, if Kentucky is promised no Louisville and UT/Vandy is promised no Memphis (Memphis is not now nor has it ever been a real option) then the crucial fourth vote to block could be removed. It won't be a hard job to convince them either because UGA,USC, and UF would turn on those guys in a second to bring in Louisville or Memphis as a 14th and they try to shut the whole thing down at that point. If Slive can convince UK, UT, and Vandy to break from the others in the East and go to a full 16 they not only avoid the teams they don't want but they most likely keep those teams out for good because the chances we ever go bigger than 16 are slim and none. At that point what is left of the ACC would be devoured by the Big East; with the Big East having a portion of themselves devoured by the Big Ten. Good Lord we really need some games to talk about!