Whether you believe this sentence to be fair or not, one fact to consider is that neither Sarkozy nor the magistrate received any of the benefits from their alleged "corruption pact." France has long been known for politicians playing around with campaign funds, but it wasn't until recently that one of them was actually sentenced to prison for such a crime. This could be the start of a new era of French justice, but it could also lead to politically-motivated prosecutions in the future.
Sarkozy's conviction shows that even the most powerful Western heads of state are not above the law. Whether it be the president of France, the US, or Israel, crying "political witch hunt" doesn't do much in a country that is ranked highly among the world's fairest judicial and political systems. It's as simple as this: the facts led to Sarkozy's downfall, and nothing else.