Alex is saying it's a 'once in a generation' decision. In other words, if he doesn't get his way on Thursday he's not going to let this bone go.
Have you only just worked that out?
It's why i said independence is all but inevitable at some point in the future. Salmond will know from his own left wing schooling that it often takes a few failed attempts before the eventual breakthrough
There are three major factors at play
1: A global trend towards more small states (about 150 were formed in the last century)
2: There is a drift towards right wing agendas which will herald more conservative governments (possibly with UKIP as a partner). It'll only require a dynasty of the type we saw '79 to '92 to push Scotland
3: The Labour party is closer now to the SDP allowing the SNP to push onto Scotland's natural socialist agenda. This will ensure that SNP governments aren't a flash in the pan
At some point in the future the stars will align again. An overall assembly majority will coincide with a run of conservatiev governments in London. All it requires than is a charismatic leader to fulfil the final piece in the jigsaw.
The SNP will keep asking for a mandate until one day they get it