Only just over half the people who voted for the Scottish National Party plan to vote for Independence for Scotland in the referendum.
There is an inherent contradiction in people voting for a party who fundamental premiss they actually oppose. Actually though it has been obvious for a long while that people vote SNP without supporting its primary policy.
A mistake many of the SNP opponents have made is to think that attacking the SNP on the issue of independence will seriously dent support for the SNP.
It is often claimed that a no vote in the referendum will kill independence for a generation - which may be true, but, will it kill the SNP ? Not so likely.
Part of the attraction of voting SNP is that the referendum acts as a brake on the SNP. One can safely vote SNP in the knowledge that by itself that doesn't mean independence. A huge part of the SNP appeal is what the americans call "pork barrell politics" - it makes the westminster government sit up and take note and start to divert fund towards scotland in an effort to buy votes off the SNP.
The SNP is not alone in this, quite often people vote BNP or UKIP. Many Green voters would be horrrified if the green manifesto was implemented. The First Past the Post Electoral system encouarges people to vote for parties other than the one they most prefer - and although it is often said the Lib Dems ask for tactical votes from Labour and Conservatives, Labour and Conservatives are always quick to say the Lib Dems are a wasted vote and the 'real choice' is between Conservative and Labour.