You're not wrong that the 'mainstream media' is biased, but it's not biased simply towards 'the Democrats'.
The media in the US exists perhaps as the most powerful and insidious tool of propaganda yet to be devised by humanity, and it is extremely effective at doing what it does best: Stirring the masses up to bicker over 2 'sides' that serve the interests of US Empire either way.
Another important thing to note is that most 'mainstream media' is in the private hands of extremely wealthy individuals or families. Of course this includes CNN and MSNBC as you mention, but it is remiss not to also include in this FOX, which is owned by the Murdoch family media empire - one of the wealthiest families in the world. They play their part doing the exact same thing CNN and MSNBC do, but just 'the other way'.
Voting for either of these 2 candidates won't actually make much of a difference. The actual important policies of the US Empire as far as trade, foreign policy, and economic policy are not decided by the American people or who they vote for as their president, but rather a cabal of powerful, wealthy interests who actually ensure that the operation and continuity of the US Empire is not interrupted.
US policy regarding war and foreign policy has actually been far more consistent and similar across presidents than different.
I disagree that voting for Trump (or Kamla for that matter) is going to shake anything up in terms of 'sticking' it to the 'mainstream media' or 'the establishment'. He's playing his part as a foil to distract people from the fact that there really isn't a real choice in this election. It's all theatrics and performative democracy, not real democracy.
If it were real democracy, then the public and the people would own the airwaves, not a handful of the richest families in the world (and yes, that includes Rupert Murdoch and Fox/Sky News). It's silly to whine about CNN or MSNBC but not acknowledge the absolute heavy-hitter that media with a right-wing bias is in the US.
Additionally, Sinclair Broadcast Group (also right-leaning) owns hundreds of local news channels in various markets and dominates the market share in that sector. Most talk radio in the US is right-leaning.
The 'mainstream media' is not biased towards Democrats. It's biased towards the continuation of the US Empire, and the perpetuation of the illusion that the American people actually have a real say by picking between 2 pre-picked candidates - both of whom are 'safe' to the Establishment.
Sure, Trump is a bit of loose cannon, but he serves the exact same interests as the Democrats serve: the whims of the billionaire donors who actually run things and stage this reality-show of an election every 4 years to make people think any of this actually matters.
Trump is as much of the establishment as any of the other candidates. He might be the 'trailer trash' of the billionaire class (as Michael Moore jokes), but he is still one of them, and ultimately will give them their tax cuts and serve their interests.
You are correct that a candidate offering anything resembling major deviation from 'business as usual' (like Sanders) will be stopped dead in his tracks.
The proof that Trump is just as much a part of the swamp he pretends he's going to drain is that he's 1 of the 2 options allowed on the ballot. He's paid his dues and kissed the appropriate rings to be cast in this role.
