Those may be offensive phrases but they don't sound particularly violent.
And to put it into slightly more context, Trump threatened to “root out the communists, Marxists, fascists and the radical left thugs that live like vermin within the confines of our country that lie and steal and cheat on elections”. And then goes on to say those same people are "poisoning the blood of our country". You can agree or disagree with his characterization of marxists, fascists, and communists but to interpret that as "all immigrants" is dishonest at best. Predictably, various media sites used headlines like "Trump tells rally immigrants are ‘poisoning the blood of our country’" and "Trump Promises to ‘Root Out’ the Left" which are intentionally misleading...and probably get more clicks.
The whole "poisoning the blood" line sounds pretty horrible, especially out of context, and he should fire his speechwriter (or stay on script) but it is pretty clear he wasn't using that phrase literally in the sense a nazi would or to imply a certain race was inferior to another. It was about actions and ideas. Trump doubles down on such phrases not because he wants to wipe certain races off of the map but because he has an inability to admit to being wrong about anything. Telling him his word choice was poor is a sure way to get him to say it again.
Along the same lines, he has said he would "implement strong ideological screening for all illegal immigrants”. I would have to hear specifics but I'm assuming this would be screening for things like if someone hates America and wants to blow shit up which doesn't sound like something most people should be opposed to.
Also, the U.S. has one of the most liberal immigration policies in the world (as it should). As far as I know, Trump isn't talking about changing that. All his rhetoric, whether you agree with any of it or not, is targeted at the 15 million "undocumented" individuals living in the country and those that enter the country illegally every day.
If anyone thinks Trump is sitting down to read Mein Kampf to get speech ideas, they are deluded.
Anyway, that's my take on it. I say all of this as someone who has yet to vote for Trump in any election.