Because they are socialists/marxists/communists. For them to gain power and control, and implement their political agenda, as Obama said, fundamentally transform, they have to destroy the current political and social structure(Constitutional Republic, Capitalism, Laws, Two Genders, etc.). It does not matter how they do it, as long as, what they are doing, gets it done.
That is why, what they say or do, does not make sense too us, unless you look at it, in that light.
So, things like, supporting illegals, they want easily controlled people, that will vote them, after giving them freebies, in to power or get them enough seats to gain power. Or, letting criminals go, they want to sew caos, in society, so, they can come in and create laws, putting more power and control, in their hands. For the people, of course.
If you look at what they say and do, on every issue, through this lens, it all makes sense.
I understand all that...it still doesn’t explain their need to go about it the way they do! They can gain power so much more easily by doing good and being honest than sowing all the chaos and division. And lying about everything. It’s like they don’t know how to real and love this country. Hate must be their life. It’s crazy.