This cartoon by Bob from the Daily Telegraph compares choosing a winner for the Grand National (a famous English horse race due to be run today) and choosing a winner in the UK General Election (due to be held on May 7th.) On the left, a blindfolded man is preparing to choose a horse to bet on among the runners and riders. On the right, he's doing the same thing with a ballot paper listing the political parties standing in the election.
Declining support for the main parties, allied with the rise of UKIP and the aftermath of the Scottish Independence Referendum mean that the 2015 General Election promises to be one of the most difficult to predict for many years. The cartoonist is making the point that choosing a winner will be a lottery, just like trying to choose the winner of the Grand National.