I wouldn't worry too much for a few reasons:
1) Fox is losing popularity, as evidenced by their ratings dip. I've been predicting their downfall lately and I stand by that prediction. They were only successful pre-Trump because back then they weren't full-breitbart and this could appeal to a wider audience. Now that they have gone full-breitbart they are losing their appeal to a lot of viewers, including moderate conservatives.
2) Trump is still getting hit with death by a thousand cuts. The same sort of constant negative narrative is what caused 60% of voters to hate Hillary and Trump is not immune to such a thing either.
3) The moment Trump actually goes down, so too does the morale of Trump's fanbase. It's the main reason (besides being primaried) that the GOP is afraid to turn on Trump and just make Pence POTUS. They know that if Trump goes down, then Pence is nothing more than Gerald Ford but with an unlikable amount of religiousness to him (Trump's rise in the primaries proves that being religious is not that appealing these days).
The only real problems to worry about for the next 4 years are:
1) Voter Suppression efforts by the GOP. Luckily it seems the Dems are getting smarter about actually tackling those efforts.
1a) Gerrymandering is still a problem that favors the GOP
2) Trump's fanbase are a majority of the GOP voters these days, which makes it hard to win over to our side any GOP politicians that rely on being voted in by GOP voters.
3) Fake News and "political psychosis" is becoming a bigger and bigger problem in America and needs to be dealt. Hopefully there will be ways to section 12 people so we can figure out cures for political psychosis.
1. Fox News might be losing popularity, but not because people prefer real news, but because they found even worse stuff online.
A considerable part of US voters are so disconnected from reality, so deeply misinformed, that it was enough for someone like Trump to become president.
2. Trump already had a dozen scandals that would've ended the careers of normal politicians. But his entire persona is built in a way that makes him largely immune to this stuff.
I am pretty sure that Trump will stay for his entire term and the way things are currently looking dems won't gain anything back in 2018 and Trump has good chances to be re-elected in 2020.
I really don't share the optimism of many liberals in the US.
Trump isn't even the problem. Trump is a symptom. The changes that happened over the recent decades in the US voter base that made Trump possible are actually concerning me.
Liberal western values aren't that widely accepted and shared in the US anymore.
And thats fucking dangerous.
A lot of Americans are scared of Muslims, scared of globalization, they don't believe in climate change, they don't believe in the must fundamental of western values.
Many Liberals seem to think that the racists, the islamophobes, the nationalists, the conspiracy theorists can just be ignored, but unfortunately these groups are now way to big to be ignored.
I just feel like Trump is seen as the problem instead of a symptom, so people are fighting Trump instead of the spreading ideology that caused Trump.