You know exactly what your assumption is because you've already argued it repeatedly -- namely that Democrats want open borders.
It's a useless discussion when someone points out any facts counter to your narrative and you just handwave them away with your own opinion.
For example: "Democrats want open borders not based on their factual record but because I read some articles about it, and Republicans aren't really bigoted -- just acceptably bigoted enough to routinely suppress minority votes and LGBT rights and to abuse the human rights of "illegals" due to concerns of an "invasion" that has inspired some on the right to actively attack and kill said people of color here in America."
It's easy to imagine people in Germany making the same exact arguments while Hitler gathered power in his country.
The more you keep trying to push the false "open borders" narrative the more it reveals how little you care that your party is racist, homophobic, sexist, corrupt, and incompetent at it's core -- if you cared about true objectivity then you would discuss said issues objectively, but instead you keep trying to frame the discussion on your own terms with "loaded" questioning because you know you have no defense for Republican behavior.
One could easily ask you why you don't concern yourself with placing "limiting principles" on the factual Republican bigotry and corruption that exists in reality more so than the hypothetical open borders that only exist in your imagination.
But the answer is obvious and asking you would lead to a dozen more pages or so of deflection -- it wouldn't do anything whatsoever to address the problem so asking you anything on said matters when you often refuse to answer honestly and directly is generally a waste of time and effort.
Your arguments remind me of how some will distract you with idle conversation while their partners rob you blind.
That said, I expect you to keep doing so even as your party suppresses the rights of minorities and continues to drive America into the gutter.