If we go by polifact (
https://www.politifact.com/personalities/), the highest rated politician has a truth rating of 14%.
From personal experience the issue we have with fake news is not caused by a president. It was the polarization from the 2016 election, which has resulted in people valuing the narrative over facts. Nothing was a clearer example to me personally when later that winter as I was participating in a conference located in Stockholm, which had a track title "Fake News", with an invited keynote speaker who was a previous board member of the wikipedia foundation. The keynote talk was made to present a narrative that media had failed to present information to the voting population about trumps scandals, and as evidence there was a image from a study showing survey result about what people knew about each candidate and their scandals. The conclusion was that if media had done their job then obviously the election would had ended correctly rather than electing Trump.
The numbers were extremely biased against Clinton and fitted the narrative so perfectly that I got a bit suspicious. Looking at the recording of the talk afterward I noticed that the evidence had a reference printed inside it. A moment later I had the paper itself, and what do I find above the image? The researcher explicitly saying that anyone reading it should not draw any comparable conclusions about the numbers as the survey operated during a period of 9 months. The researcher noted that if they had done a new short survey closer to the election date then the numbers would look very differently. It pretty obvious that people can not answer a survey with knowledge of scandals that occur in the future.
Fake news will continue as long we try to make facts fit a narrative, rather than first looking at the facts and then construct a theory about the world.