As an outsider (to SWA), I find this is a good move, but it will only have any significance at all if it results in significant modifications. If it goes back in for a little tweaking, just enough for 50%, and passes again, it may make you feel a little better for voting it down, but that's about it.
If on the other hand your negotiators see this as a major rebuke, or if your union changes negotiators altogether, with instructions NOT to come back with a "51%" T/A, then this will be a turning point you should be proud of, and we should all envy.
For now, congrats for putting a marginal T/A out of its' misery.