@TomFromIsrael,
You're speaking of two quite different things. First, there is no opposition (that I've ever bumped into) to immigration from Israel into the US (other than from a very thin sliver of the population who are actual anti-Semites).
But the other part of your question - influence on US government policy exerted by either Israel or by pro-Israel persons and entities within the US - that is a different matter because it may effect American sovereignty and because it may happen out of sight of the population. But in this, Israel is no different than any other nation.
I'm Canadian. Here, we have traditionally had concerns about America exerting influence over Canadian government and policy. That involves issues of related to the imbalance in power and wealth. But we have no concerns regarding an American moving north to live in Canada.
Does that make sense to you?