The word radical comes from the Latin radix, and means basically to tear up by the root. While in a phrase regarding terrorism it may not be particularly apt (far as I am aware, jihadists aren’t radicals in the strict sense of the term, where something like fanatics or zealots or even blood-thirsty dipshits would better serve), it does fit at least some of Trump’s political stances. Note that I am not using the term radical pejoratively, but trying to look at which policies are accurately described that way.
Trump is a radical on many issues, both across political lines and within his party. A ban on Muslims immigrating would be a radical departure from the First Amendment to the Constitution, where the government has long held that religion is the individual’s business. Building a wall, while not radical in some circles, would be radical for national policy that has held that border protection requires more than mortar and brick.
On trade, in particular, a move toward an anti-trade stance, predicated on some bizarre notion of trade imbalances being detrimental rather than seeing the dire need for workforce enablement through policies that are compatible with trade, is radical. Same on dissolving the accord for blocking Iran from acquiring nuclear armaments, same for the notion that allies should gain nuclear armaments, same for the weakening of NATO, and so on.
The man literally wants to tear up some of our treaties and agreements, including commitments on climate protection. And his whole America First foreign policy, which suggests the idea that we would sell out our allies if it benefits us, is entirely radical and isolationist in an era where America has never entertained such ideas.
On the other hand, some of his policies are the epitome of the status quo. Take his stance on healthcare reform, for example. Repealing the Affordable Care Act may seem radical, but his policy recommendations mostly focus on minor tweaks to things like tax deductions and health savings accounts. In an area where we probably need more radical changes to actually move the needle, Trump is go-along-to-get-along.
So, the question is, is it fair to call Trump a radical? On some subjects, undoubtedly. But as I have pointed out before, Trump’s policies vary from the bizarre to the GOP party line (some of which overlaps the bizarre and radical, but a lot of which is just banal). The overarching policy of Trump isn’t radical as much as it is a reflection of his belief that America is diminished.
Usually that sort of mentality results in revivalism, the belief that return to earlier forms will restore the prestige and power. That can be seen in the slogan “Make America Great Again,” but very little in the policy and even less in the reality. Is America numero uno in all of the ways we could be? No. But none of Trump’s policies really address those things.
If Trump were an across-the-board radical, we would see policies on diet and exercise, on educational spending that would make our heads spin. We would see him calling for interstate-highway-system-scale initiatives on broadband and public transportation. Policies that could actually have long-term impacts on how we live. Instead, the crown jewel is a wall. The foreign policy and the trade policy are walls (figuratively).
The Latin for wall is murus, which would make his politics mural. Which probably fits. His policies are entirely two-dimensional artistic interpretations of realities meant to evoke emotional responses in the viewer.