As you said, gambling is just for fun. Not addicted, or anything that can harm your reputation, but just for fun.
It is indeed that reputation is important when you're running as a counselor or in any position in politics, but I don't think that it will affect your reputation. As long as you can provide proof of where you get your money, there is no need to think anything about it.
Still, being a gambler can ruin one's reputation for sure cause if you are going to consider some other vices that sticks together with gambling, it can be a source of corruption or even crimes. You can choose not to stop gambling but make sure you can hide it from everyone else cause once it gets out in public, your reputation will definitely be harmed.
i always Hate seeing politicians in news that gets involved in Gambling because it looks like they are also gamble the future of their people.
as i believe that once a gambler will always be a gambler and having this attitude will also apply in their administrations.
so if i am to vote?i will never vote a Political person that involving in this kind of activities,this is my stand and will always be.
It is quite funny that many local politicians in my country are very much into gambling. As a matter of fact, I have heard several times how people appreciate a politician who is considered down to earth because he is found rubbing elbows with ordinary folks in cockpit arena and local gambling houses. Normally, the older people who are a bit conservative would frown at them but the younger generation wouldn't really mind them being gamblers.
That is the reality, there are people who see it cool for a politician but majority of people would not see it that way.
It differs from country to country but politicians will try to look clean all the time especially if they are running for a higher office, maybe OPs example is not an example of a politician running on a high office but the more you run high the more people you will have to impress.
In our country's history, a current president was caught in the act of gambling which eventually led for the people to push him out of his position. Indeed it varies from different countries but for a third world country like ours, it can be seen as a clear corruption if you were to be caught gambling as a politician. It's probably people's taxes you are using to feed your greed for money.