The United States has tens of millions of illegal aliens residing within its borders. President Trump is the chief law enforcement officer of the nations. One might believe he has a duty to enforce the laws of the nation; that it would be an impeachable offense to be derelict and indolent and choose not to enforce the laws. Democrat party leadership tends to disagree with that position concerning the illegal aliens.
The L.A. Times has reported that illegal aliens are calling people in virtual terror of law enforcement activity the President said would include rounding them up for deportation.
If the President were to selectively enforce laws, that would render the courts and congress to a superfluous status (if he could get away with it). A President could order the I.R.S. not to collect taxes on the rich (though President Obama already cut their taxes to a minimum), not to enforce laws against defecating in the streets of the nation’s capitol as free speech about Democrat Party legislation, build a seige tower in front of the White House as politically protected free speech or enforce laws against pollution or insider trading. Democrats like illegal aliens and open borders for various reasons including yet not limited to anarchy and global communism. They demand executive compliance with their will regardless of the legality or means required to get it done.