Immigration - I think that's contested. A lot of people in the middle/right think the left (particularly far left) favors illegal immigration because immigrants may be more likely to support their aims. I think the truth there is mixed, but I don't think it's wholly inaccurate. But moreover, it doesn't matter what they want, it matters what people see them advocating for. When Trump goes "build the wall!!!" and the left hates Trump so much that they start backing up sanctuary cities not turning over criminals in some misguided knee jerk reaction, portions of the electorate are going to draw conclusions whether that fairly reflects the position of the left or not.
Discrimination/income inequality - People care about these things in a vacuum, but they're told (by the left and non-conservative media) that we're in crisis. Most people probably don't see or feel that crisis right now.
I do think the average voter hears about wealth disparity and goes "yeah bonuses for CEOs are insane, what about the little guy, right?" But that doesn't mean income inequality is something that truly resonates with Americans and impacts elections. Partly because you have Nancy Pelosi out there disparaging the bonuses and wage hikes from Starbucks, Apple, AT&T, Verizon, etc. That stuff matters to people. They care about inherent unfairness to an extent, but I don't think theyd care about some Piketty-ish macro war on income inequality and the wealthy.
Similarly, I think most people see Charlottesville and go "yeah that's messed up, Trump shouldn't be coddling people like that." But then they watch BLM, ANTIFA, the Women's March, etc. for months and months talk about oppression in America, and the felt/seen oppression among your average voter is pretty negligible. And what's more, people (probably mostly white) look around and go, where are these white supremacists, I've never met one? Where are these people using racial slurs? I never hear them. They see cops committing abuses toward people of color, and I truly believe most abhor it, but they live in areas where people of color commit a lot of the violent crime. That taints the concept that the majority is somehow some existential threat to the minority.
Average people look at the Women's March and go, "I'm all for female empowerment, but where is this dystopian Handmaid's Tale universe?" I think we all agree that the #MeToo movement has genuine life and is indicative of genuine, wide-ranging abuse (unfortunately, now people are moving to where bad dates and regrettable sex partners are being lumped in (see the Aziz debacle) and it's probably watering down a legitimate national problem). But people see signs saying "equality of opportunity for women!" and that just doesn't make sense to the average American that knows women are often viewed more favorable by colleges, government and professional employers.
I know that's long winded, but I just think there is a huge disconnect between what the left is messaging, and what actually hits home with average people. And I think solely looking at poll numbers that say "do you care about income inequality" and drawing from that is going to be a mistake for the left from a political messaging perspective.