Equal Protection, Right to Travel
State statute offering tuition benefits for past military service so long as the student enlisted or was inducted while in the state or a resident in the state has a rational basis, as it encourages positive behavior (enlisting, graduating high school) and keeps other residents of the state from being conscripted.
Right to travel is not implicated, as it imposes no penalty on entrants to the state. Had it been implicated, portability of of benefit and gratuitous nature of entitlement would suffice for review.
Keith Harris v. Texas Veterans Commission, et al
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.