I’ve noted many times that polls prior to primaries are of little predictive value. Polls in December 2007 showed that Clinton had a huge lead over Obama. In December 2003, Howard Dean was pulling away in the polls. Eventual winner John Kerry was in sixth place with only 4 percent, even trailing Al Sharpton. While Clinton is certainly in a strong position this year, her leads in the national polls do not guarantee victory. Similarly, while Donald Trump seems to have a significant lead in the Republican race, it is premature to assume he will win unless he actually performs well in Iowa and New Hampshire.Alfred J. Tuchfarber has looked at the December polls and has also demonstrated how little predictive value they have. In polls from November 2007, taken two months before voting, Hillary Clinton was leading the Democratic race. Rudy Guiliani was leading the Republican race, with Fred Thompson also ahead of John McCain. In 2011 Herman Cain was leading the Republican race, and had left the race by the time of the Iowa caucuses.