Since I’m only partially serious here, I figure the PIt is the most appropriate place for this thread.
Let’s go back to the Bush years. Let’s remember two fierce Bush critics from the paleocon side of things, Pat Buchanan and Lou Dobbs. Both criticized Bush for things like the Iraq war, which liberals cheered and rightly so, but both of them were also going on about outsourcing, trade, and immigration. For a few years they had pretty much zero pushback on those subjects, because the right sorta agreed with them on those issues even if they didn’t like their criticism of the Bush administration, and liberals didn’t really push back because they were following the ancient “The enemy of my enemy is my friend” doctrine. So Dobbs especially spent years telling viewers that their problems were being caused by the Bush administration, and also brown people, whether overseas or coming into this country. Once Obama was elected and Dobbs’ xenophobia transformed into birtherism, he was forced to resign from CNN.
While I’m only partially serious in that Buchanan and Dobbs did not lead directly to Donald Trump, their arguments which went mostly unchallenged and seemed to be non-partisan, which gave them a better rep among independent voters than would have been the case had they been seen as partisan hacks, certainly contributed to the spread of anti-immigrant views. If liberals hadn’t been so eager to tout Dobbs as reasonable right wing voices he would never have gained the traction he did, and Trump might have had a few hundred thousand less supporters than he does now.