I'm going to take an unpopular opinion here. Trump isn't the enemy.

[BzaDem]

80. Trump is a mentally unstable man whose careless tweets can set in motion events that lead to war.

You are right that getting rid of Trump will not somehow cause progressive policies to be enacted, or stop the tide of conservative policies from being enacted. All the people you mention (Koch Brothers, Mercers, etc) are not going away.

But that is true no matter how much we "put aside our differences and go after the big bosses." Of course the right will not go away. They are one of the two parties in our two party system. The right, and its power brokers, are here to stay, and nothing we could possibly do would change that. They will continue enact deeply harmful policies and attempt to entrench their power. (Though with respect, claiming "they will do more damage than Hitler/Al Qaeda/ISIS ever could" is ridiculous, and I hope that is self explanatory.) We can of course highlight the consequences of their policies with the aim of convincing voters to vote them out. (And Democrats are doing that every day.) But many general "fight back" tactics have limited effectiveness in affecting policy, particularly this far out from the next election (absent some major event that captures constant media attention, like the healthcare bill).

While the institutional right isn't going anywhere (regardless of what we do), the same cannot necessarily be said of Trump. Trump is mentally unstable. He thrives on chaos, and attempts to cause it however he can. He does not even understand the concept of caution, and disdains the very notion of listening to advisors (even those who are ideologically aligned). This set of factors dramatically increases the risk of an otherwise preventable cataclysmic event. After all, if Trump tweets us into a war that kills untold numbers of people, can you really say "well he didn't look that dangerous at the time, no one could have foreseen this"? Given everything we know now about how he chooses to conduct himself?

In addition to Trump being uniquely dangerous, he is not at all liked by most Republicans in Congress. They are standing with him today because the base still supports him (and because of political inertia), but that is not set in stone. If Trump continues to show in ever-more-frightening ways that he is unfit for office, his support (in Congress and among the public, which affects his support in Congress) could spiral downwards or collapse. Any actions Democrats take to highlight his unfitness help lay the groundwork for Trump leaving the Whitehouse, either before or as a result of the 2020 elections.

On top of that, one of the single biggest factors that affects the success or failure of Republican policies is Trump's approval rating. A low approval rating portends disaster for Republicans in 2018 and 2020, and they are going to be less likely to take legislative risks the lower it goes. A low approval rating also scares off competitive Republican Congressional candidates, and generally increases the odds of success for Democrats in 2018 and 2020.