I really think the middle path would be broadly popular, but it's just that it would be unpopular with the loudest voices online (on both sides), thus making it appear unpopular.

That middle path would be:

• Tighten up actual border security
• Higher standard for refugee status; stay in your country while asylum case is processed
• Stricter enforcement of visa overstays and other abuses like continually re-enrolling on student visas
• Pathway to citizenship for those who have already been here a long time and are working and paying taxes
• Cooperation between federal and local law enforcement for illegal aliens convicted of crimes