I think that at the moment people have very strong reactions to the right. General Mattis sums up why fairly well. People are watching the Trump administration and realizing that he's actively trying to divide us. Whether he's an accurate spokesman for the right or not, he is the example that everyone sees because he's the Republican president. Because of Trump's rhetoric and division, they see him and by extension the rest of the right as an existential threat in a way that they don't see leftists or centrists. Pre-Trump, Republicans and Democrats felt like they were just two groups of people that are probably corrupt but can get something done right on occasion. Now, it feels like the Democrats are still like that, but the Republicans are more powerful and threatening. Until Trump leaves office, I don't think it's gonna be popular to be on the right, even if you disagree with the measures of division and authoritarianism.

Public perception is the most powerful thing in politics, and the perception of the right at the moment is that of something to be feared.