For people who feel a sense of civic duty – a determination to do what they can to improve the laws and policies of their society – it seems to me that there are multiple valid avenues through which to apply your efforts.
The most overt may be entering politics, but it is an option that carries many costs. You might have to spend a lot of time at small-town barbecues wearing a silly apron, to try to convince voters that you’re an ordinary guy like them and not some fancy-school elitist. You might also have to lie about or conceal beliefs that go beyond what the mainstream is willing to accept (better not be an atheist, for instance). Still, if you do take the political route and find yourself in a position of influence, at least you have a pretty defensible mandate to try to implement the ideas you campaigned on.
The civil service is another option. The influence and the constraints of the civil service are both tied to the same role: providing advice. Being someone who provides advice gives you the freedom to use your judgment and the best available evidence to suggest a course of action. The trouble is, you can always be over-ruled by your superiors or by the people who ultimately make the decisions. Civil servants therefore have a moderate level of freedom for expressing their honestly-held and well-justified views, but little certainty that their advice will ever make a difference.
Journalists and academics have the most freedom to speak and defend their arguments in public, but they have even less certainty that their efforts will ever produce concrete changes. Judges, by contrast, know their judgments will have concrete effects, but they don’t know whether that influence will be confined entirely to the case at hand, or whether it will become a more influential precedent.
Setting aside the advantages and disadvantages of different roles, I think it is important to acknowledge that people in all of these roles can be doing their civic duty, in the sense of trying to serve the best interests of their country and the world more broadly. It is possible to serve those interests through obedience – for instance, those who put themselves in physical danger for the good of others – but it is also possible to serve them through honest and open criticism. All governments have made serious mistakes in the past and face major challenges today. If we are to navigate successfully to a safe and comfortable future, there needs to be energetic and open debate based on the best evidence available.