Final answer:
The Scottish National Party (SNP) does not need reauthorization but its legislative proposals would require approval from the Scottish Parliament or the electorate.
Step-by-step explanation:
It seems there may be some confusion regarding the term 'SNPs' as it can refer to Single Nucleotide Polymorphisms in a biological context, or the Scottish National Party in a political context.
Based on the sources provided and given the involvement of Sir John Curtice and The Scotsman, it's likely the question refers to the Scottish National Party. The Scottish National Party (SNP) is a political party and it does not require reauthorization.
However, the legislative actions or proposals of the SNP, such as a bill for Scottish independence or other governmental measures, would need to pass through the Scottish Parliament or potentially be subject to approval by the electorate through a referendum. The SNP is responsible for advocating policies and can be influenced by public opinion, as indicated by drops or rises in support for Scottish independence.