The proliferation of lies: Media in the post-truth political era

Welcome to the new age of "post-truth politics" - an age in which the legitimacy of politics is not only constructed upon a scaffolding of lies but even more so  based on the assumption that truth or facts no longer matter. What role does the media play in this statement? Does it matter if politicians and influencers leave the truth behind entirely? Are mainstream media losing their identity by branding false statements for the lies they are? Or is the lesser evil keeping silent instead of stigmatizing the big players of the world? How can media rebuild trust in a post-factual time?