But McDonald - who tracks how many early votes have been cast and, when possible, by which political party - says that it may be possible to determine the eventual winner by watching hotly-contested swing states.
Professor Paul Whiteley of the University of Sheffield calculates that the 17% by-election swing from Labour to Liberal Democrat would be enough, if repeated in May, for the Liberal Democrats to seize Sheffield.
This far in, it's obvious what to expect: pickin'-party songs, bar-band basics enlivened by loose, easygoing solos that traverse Western swing and Stardust-era Willie Nelson.