One thing we know virtually nothing about in Trek is Federation politics and its relationship to the media.
Given the recent election cycle in the United States, one cannot help but be struck by the so-called "mainstream media" and its effects. The primary news services in this democracy are strongly leftist and admit being so (e.g., Ted Turner regarding CNN, et al.), in keeping with what seems to be an international state of affairs (i.e. the BBC). Further, although there is now a lone major news network that is further to the right, the overwhelming majority in print and television means that the issues get framed by them, limiting the minority channel's capacity to focus on stories the leftist media chooses to ignore. And there is no significant centrist media.
While the leftist media has colored a wide variety of issues and selected an amusingly leftist-helpful array of stories to focus on in the run-up to the recent election, perhaps no better evidence for the point can be found than in regards to economics. By all indicators the United States economy is doing extremely well, breaking records in some cases and posting the best numbers in decades in other areas, but the leftist party and the media have continually argued that the economy is in shambles, troubled, and so on, a reality-bending which seems to have successfully made its way into popular perception. With the strong gains by the leftist party (due in part, entertainingly, to numerous centrist candidates), though, the international markets have suffered a bit of a tumble, recognizing that the strong U.S. economy will probably now fall prey to leftist damage. But I digress . . .
Chances are extremely good that the Federation is strongly leftist. While the communism claim folks make about it is a load of hooey for reasons to be elucidated in a future article, the fact is that folks who are separated from the realities of production . . . i.e. people who view food as magically appearing from McDonald's instead of recognizing the farmers and all the steps to get it to the restaurants . . . almost invariably break left. Similarly, urban areas break left in modern times, for similar reasons. In an age of replicators this effect could only worsen.
In the modern era, leftists have (as a rule of thumb) been weak on defense. Of course this isn't necessarily so everywhere . . . witness Soviet Russia . . . but overall the point holds. The inherent lack of understanding of objective issues like food production generally extends to other spheres, so that obvious threats are appeased and the spilling of blood for any reason is unpalatable.
(Trek's writers seem to grasp this if even on a subconscious level. Most of the best Starfleet officers are seen as coming from right-leaning backgrounds . . . Picard's family worked the land and rejected replicators, Kirk spent time on a farm in Iowa (and also witnessed evil early in life), O'Brien's family rejected replicators, and Sisko's father ran a restaurant and had some views best described as libertarian.)
But, alas, there are too many unknowns in regards to the Federation political sphere. As far as we know, they might've followed George Washington's suggestion to avoid political parties altogether. And although we've seen press in the Federation before (in ST6 most notably), there's no way to know its leanings.
Some have claimed, though, that the Federation News Service seen in ST6 is evidence of a state-controlled media. Of course, that's no more likely than the American Broadcasting Company being state-controlled (it isn't). However, I can't necessarily say that a free media with a state-controlled popular media outlet also in existence would be a bad thing.
But Trek is about optimism, so perhaps the best idea is that parties don't exist in the 24th Century, and that the media of that era is not one attempting to serve certain interests, but instead just tries to report the facts and not shape them.