The situation is not good but let’s not lie. Green card holders returning from overseas have always been at high risk of encountering issues upon reentry. Overseas visitors working informally have likewise always risked detention and deportation. The gentleman in Boston was treated very badly, but his detention lasted hours, not days. Ordinary tourists are not being detained. I am a US Citizen who worked in the EU for some time and was detained upon initial arrival into the Schengen area while they checked into my work visa. The French scientist situation - very concerning, but they were just sent home. Hardly a reason to withhold a visit “unless your life depended on it”