It seems to me one of the methods of control in oppressive States is to have a multitude of rules, which are impractical to actually adhere to, where failure to adhere provides leverage to State - a "justification" for State to then do whatever it is it decides to do with you (such as deportation without due process).
Play the devil's advocate with me for a bit. Say you let someone in who suicide bombs himself and takes out several Americans. Then a reporter asks the DHS spokesperson how they let someone in the country that had "Death to America" posts all over their social media out in the open for everyone to see but they didn't. Nobody would forgive the government for such a grave oversight. At the airport you already let them…
Everything is partisan now.
If something bad happens, every media outlet will blame the party they don't like for it somehow. It doesn't matter what that party actually did, therefore there is no value in doing harmful stuff for CYA purposes because deploying the CYA tactics will not stop you from being blamed for it by the outlets that don't like you, and also will not stop the outlets that do you like you from blaming the other party instead of you.