There used to be clever and amusing TV adverts with the punchline "Happiness is a cigar called Hamlet". They stopped way back. Maybe now they sponsor Shakespeare plays in return for product placement. Was that guy in Denmark always called Hamlet?
Happiness goes in and out of politics. In the early 19th century Jeremy Bentham, many of whose ideas presaged scientific totalitarianism, said the aim of government should be "The greatest happiness of the greatest number". This is more or less accepted by a lot of people, and the old objection that you can't measure happiness has to some extent been answered by pollsters who can ask people how happy they are and count the results. It has strengths: if the whole population is miserable, one would expect a government to try to do something about it, and a focus on happiness prevents a narrow focus on, for example, economic growth or national aggrandisement. However, Bentham's formula implies that if we could make the great majority of people happy by unlimited oppression of a minority, we should do it. As a "deep Green" I don't think values should be based purely on human happiness, ignoring other life-forms (though I recognise political reality, that in human society human interests will come first and others may be decisive if the human interest debate is evenly balanced) and as a Christian I don't accept that the main human goal should be happiness, but awareness and love - still more difficult things to measure.
Consider this question I put to a friend who has deep moral convictions which seem to exist separated from his political philosophy. Imagine a society with slavery. The free exist happily without bad consciences on the proceeds of the slaves' work and the slaves, not realising they could be free or scared at the prospect of freedom, are content being slaves. Into this society comes someone preaching against slavery. Do you support or suppress him or her?
When I continue this post I'll talk about the British Government's "wellbeing index" which has been laughed at, preached against and praised as setting up happiness as a government goal.