I can't speak for the media in the UK, but in the US it's clear there already are (and have been for a long time now) forces at work in the media controlling the agenda and pushing specific narratives. Fox News has had success branding themselves as the 'alternative' to the mainstream media, but in reality they do the exact same thing and are no better (they just have a different agenda). Ultimately, I suspect the majority of the trouble the news media in the US has been having are due to generational trend changes (different ways they get news), a decline in the quality and independence in their reporting, and close attachment to certain political and corporate interests. While there are certain people who want to destroy the media altogether for their own purposes, in reality the news media's trust problems are largely of their own making. We can only hope some of the smaller, independent news companies and journalists step up to fill the void.

As for the US politicians, what you say applies to the US too. The biggest problem is the dysfunctional political system itself and the system of perverse incentives that are inherently corrupting. Despite that, there are some politicians that appear to maintain some set of principles and integrity (even if I might disagree with them on issues). But then their party leadership works to prevent them from getting nominated for the highest positions in defiance of what their voter base wants. So it's not so much that all politicians suck, rather it's the questionable ones that tend to make it to the most influential positions in the gov't and largely run things. Hence, the line "worsening pick of ass-clowns"... we only get to pick among bad options.