The Democrats intentional looking piss poor election performance is evidence of the system being rigged
Obvious from the get a Trump win was going to happen and was so by design
Otherwise the Democrats would have fought harder instead of blatantly pissing away every advantage and opportunity that could have guaranteed a landslide victory
That part is true, but that doesn't mean you need to lurch into conspiratorial thinking to try to explain it.
There's a much simpler explanation: the Democrats did what their large corporate donors forced them to do in order to continue receiving the bribes.
It's corrupt, but it's neither a conspiracy nor required any sort of coordination with the Republicans. It's simply an emergent property of a plutocratic system.
The system itself has to be dismantled; singling out the participants in it for individual/single group blame feels good and is morally justified, but doesn't actually work to solve the problem.
In other words, you largely aren't wrong, but you wrote it in a way that made you sound like an unserious nutjob. If your goal is to persuade, you should rethink your phrasing.