I would agree, Representative Omar's remarks are not anti-semitic, just because she is critical of American support for Israel. US support for Israel is like most of its foreign aid and support, it is really a way to extend American military and economic power over a region. There are some conservative politicians who are influenced by evangelical premillenial dispensationalism as well.
What Israel has done to Gaza is unconscionable. We've gone to war in the past over that kind of oppressive treatment of countries and people groups. Supporting that is anti-Christian.