Antisemitism really bugs me. I know that my fellow Republicans agree with me on this, because no person should be singled out on the basis of their religion.
The most common religion in the US is Christianity (with 'secular humanism' close on it's heels). Christianity is based on the teachings of Christ (a Jew) so antisemitism is anti-christian; people may tell you differently, but do not believe them. Antisemitism is anti-christian.
Christians believe in what we call the 'Old Testament', which is the same book as the Jewish holy book, the Torah. Actually it is the Torah plus some other stuff. What really differentiates Christians, though, is the 'New Testament', the teachings of Christ. Nothing in the new testament speaks in favor of religious discrimination. There is nothing that says that non-Christians should be treated differently, and the theme is that all your fellow men should be well treated.
But being against religious discrimination does not mean that we cannot speak against religions that discriminate.
I have known Hindus, Jews, Sikhs, Buddhists, Muslims, and all kinds of Christians. As individuals, we sometimes have our prejudices, which we know we cannot hold against individuals, because each individual is not just their religion. But if you know someone who wears the hood of the KKK, it is difficult not to paint them badly by their association, and probably it is a good thing to challenge them on this.
I know of no Hindu, Jew, Sikh or Buddhist who teaches that discrimination against individuals of other religions is right. I am sure there is a small minority, but I do not know of any, and I feel certain that any such views would be ostracized by our religious communities. Of Christianity, I am more critical, since it is my own religion, and I feel responsible to keep clean my own house. No individual who speaks of discrimination as the teaching of Christ is a brother of mine.
The trouble comes, of course, with Islam. Let me start by saying that I have known many good Islamic men and women, and that nobody should discriminate against a person based on their being Islamic. But good men are good men despite being Muslim, not because of being Muslim.
Many current Islamic teachers claim that Islam dictates that discrimination is right. Islamic law dictates that Christian and Jewish houses of worship, should not be allowed to be repaired, and should fall into ruin. Christians and Jews should be treated differently under the law; Muslim converts to Christianity should be executed. These are not just teachings, these are beliefs held by many Muslims, and the basis of many laws in Islamic lands. Even in so-called 'Moderate' Egypt, Muslim converts to Christianity are at best harassed, and it is reported that an overwhelming majority of Egyptians believe they should be executed.
It is very difficult to square these negative aspects of Islam against the freedom of religion we have in the United States. Islam as popularly practiced worldwide more resembles the KKK than it does any other religion; it seems at odds with our society to stand in favor of such a religion.
I do not suggest the US discriminate against individuals, but we must recognize that though we may have many friends in Islam, Islam itself is not our friend, and cannot be our friend, until it teaches tolerance and equal treatment of other religions, and of members of other religions. And just the words of one teacher are not enough. All those who teach discrimination must be ostracized. Just like we do to the KKK.