Why should citizens believe they have the right to live where they do? Just because they were accidentally born there? The only people who have earned the right to live anywhere are those who have gone through a citizenship process, everyone else it was handed to them by accident. Illegals have generally done more to earn their place in the US than someone born and raised there.
Considering the US has profited and encouraged illegal immigration for several decades it isn’t surprising that sentiment has become more common.
Both sides of the isle did nothing because they benefited from it, cheap labour which didn’t get the same rights as a American citizen, essentially replacing slave labour and allowing the US to compete economically with many 2nd and 3rd world nations in labour costs.
They literally had illegals paying taxes which meant they couldn’t receive the benefits of said taxes but were paying into the system.
Those citizens rioting/protesting don’t see them as illegals, they see them as neighbours, friends, family. In many cases they have lived/worked with them for decades. Why would they want them deported?