If they simply declare that they are servants of the people and that they will do as the people will despite sometimes disagreeing, that's fine.

But what many politicians do (no idea about Merkel, but I've seen it a million times elsewhere) is take the public opinion as their own. If public opinion supports X, they will say that they believe X. If public opinion shifts and then support Y, they will not only say that they now believe Y, but imply that they always believed Y.

I realise that this is a tricky question, but I think that politicians should act in the best interest of the country for the long run and this may necessitate making unpopular decisions in the short term that may even go against the majority's opinion.

Let's view this from the other side. A politician promises to cut taxes for everyone by an amount of x after being elected. Doing so will require cuts in other budgets. I don't think the majority of people will reason that although it would be nice to have a bit more money in the pocket, it is a better idea to spend that money on say the educational system.

My experience is that very few people are really interested in seing the bigger picture and much fewer even in solving those issues.

I think it's more of a attack on the two-faced deceptiveness that politicians usually exhibit, and the demand for "unpopular choices" is more of a demand for consistency in the face of opposition looking to score political points on a hot-button issue.

Interestingly, Thatcher was known for ignoring pre-election opinion polling statistics (she personally identified herself as a 'conviction politician') and instead pointing at her unbeaten election record. This stubbornness was in fact key to her downfall, and the rest is history.

There are alot of good long term decisions that are unpopular in the short term. Merkel mostly optimizes for a positive short-term outcome, especially this close to the election.

Thats more like a global problem with the current form of democracy though.

Yes, and there are lots of popular short term decisions that would be terrible in the longer term. Lower taxes, yay. Block immigration, hard on crime with long jail terms for minor offenses, deregulate banking etc. Just recently I had a friend who voted for the party that promised to lower taxes complaining about the lack of staff, being overworked and not having a pay rise. He works in a publicly funded institution. People don't seem to think even 2 steps ahead.

Exactly...most of the countries with really high taxes are the most stable financially for example.