First, I strongly disagree that Omar’s comments were racist and I will always condemn apartheid and human rights abuses whether or not Israel is the culprit.
Second, the purpose of bringing up white nationalists was to show how Trump communicates these racial discontents, not to show that all Trump supporters are sympathetic to their specific cause per se. Although I will tell you these views are not particularly fringe anymore, especially in the online sphere where people have some anonymity.
As far as policy action, his main policy achievement is the tax bill which disproportionately benefitted the wealthy. His draconian border policies and abuse of the government shutdown to that end was also harmful. I do however support the prison reform bill and his (supposed) positions on withdrawing from the Middle East, even as he has recently walked back his Syria withdrawal and continues to support the Saudi destruction of Yemen. He’s effectively acted as any other Republican despite his rhetoric which is perhaps a bit of a betrayal of his base. But, of course, he was an obvious charlatan from the beginning.
As a Leftist I reject the mainstream liberal narrative that trump voters are simply ‘bad people’. These racial anxieties do have a material basis in economic malaise brought on by long term flat and declining real wages among other things. The mass alienation from labor, society and politics will only be further deepened by the churn of neoliberalism unless something is done. But economic/racial nationalism is a false savior even for those it purports to aid. Not to mention those it condemns.