It's not racist, it's enforcing the law -- which is to some extent his job through allocating resources and people to these tasks.
It's also worth noting that in his policies he's generally not "rounding up everyone" and rarely if ever enforcing immigration on otherwise innocent people -- the thrust of his efforts have mostly been in regard to people who are criminals or who failed to show up to court for asylum/immigration hearings. To me, that policy is too lax -- I view all illegal immigrants (regardless of origin and ethnicity) as criminals by default. No other country would put up with this silliness nor should we.
It's also worth noting that Trump's support with African-American and Hispanic voters whom are legal immigrants has gone way up, mostly because now they're financially getting some where. It's more likely that the "jobs stolen" are being stolen from legal Hispanic immigrants more than anyone else. If he was so overtly racist they'd not support him.
I don't know that anyone is saying that he's
overtly racist. He might be a soft racist. I never did put much stock in the comparisons of Trump to Hitler, but maybe he's closer to Archie Bunker. If Hitler is a hard racist, then Archie Bunker and Trump might be examples of soft racists, or "racist lite."
That may be part of the issue, since the current narrative seems to imply that unless someone is 100% "pure" on this issue, they're just as bad as Hitler. The insinuation is that "racist" = "Hitler" = "deplorable." This is why the response to such a charge leads to the conclusion that "since Trump is not as bad as Hitler, therefore he is not racist."
The current dialog ostensibly implies that racism is an "either/or" proposition, suggesting that if someone isn't 0% racist, it automatically means that they're 100% racist and a genocidal maniac (Hitler). That's why discussions about race in America usually tend to go haywire like this.
As for immigration, part of the problem are the immigration laws themselves and the government's overall refusal to implement any real reforms or changes to the law. But previous administrations weren't really enforcing the law. They were treating it with a nod and a wink, while understanding that to enforce the law to its fullest extent would be unfeasible and politically inexpedient.
But then, they didn't do much to actually change the law, so now we have a situation where Trump says "I'm going to enforce the law," and people are responding "No, wait! You can't do that!"