Look, you spray disconnected fragments of information and half-truths, making a splendid mess of things in hope that when the dust clears someone will be convinced that Arabs have more claim to Israel than Israelis. But you fool nobody. Lets restore some order shall we?
Semites is a name for all sons of Shem, among which are the Hebrew people, whose ancestors are the Jews, and various other descendants who are considered ancestors of the Arabs (that part you got right). So both Arabs and Jews are Semites. To claim that a Jew from the US or Poland or Morocco or Yemen or wherever is not a Semite is just like claiming that an Arab living in Morocco or Yemen or the US is not a Semite. The days of the Bible were a long time ago, and both Jews and Arabs were genetically mixed with other peoples to some degree.
However, Jews maintained their identity and cultural and religious heritage, while living among other nations, throughout thousands of years. Despite your attempts, there is not nor has there ever been any missionary activity to convert people to Judaism - on the contrary, converting to Judaism is a very long, difficult and demanding process, never encouraged by the Jewish clergy, and only the most determined ever succeed.
"Palestinians" on the other hand is just a group term for all sorts of immigrants from all over the Arab world who today live in Judea, Samaria, and Gaza. They have no collective history or common roots. The only thing that unites them is that they live nearby Israel and hate it.
Trying to play the racial card in favor of the Palestinians' right to the land gets you nowhere. The Jews' cultural and religious ties to the land of Israel never ceased even thousands of years after they were exiled from it. Although there was some mixing, Jews in the diaspora generally stuck together and did not disperse among other peoples. On the other hand, what difference is there between an Syro-Palestinian Arab in Syria or Jordan, and a Palestinian in Judea Samaria or Gaza? Zilch. Just where the border passes.
It is true that a Jew who lived many generations in the diaspora is likely to be mixed to the point where he or she can't claim to be a pure-blood descendant of an Israelite who lived in Israel in Biblical times, so what? Because Jewish identity was preserved so well, it is to a much greater degree that a "Palestinian" cannot claim he is a pure-blooded ancestor of a Canaanite or any other son of Shem. No amount of pseudo-logical tap-dancing will make it so.
So you can be in favor of a new Palestinian state if you want, to live side by side with Israel, the only Jewish state, and the other 3 Palestinian states that already exist (Jordan, Syria, Lebanon). But trying to deny the claim of the Jewish people to the land of Israel with claims such as yours is simply worthless.
Moving on, Antisemitism is a term used to describe prejudice against or hostility towards Jews, even though Arabs are Semites too. The term mainly originated when Jews were persecuted in the diaspora. If you don't approve of the definition, go write your own dictionary and see if anyone buys it.
http://en.wikipedia.org/wiki/Anti-SemitismAntisemitism (also spelled anti-semitism or anti-Semitism; also known as Judeophobia) is a term used to describe prejudice against or hostility towards Jews, often rooted in hatred of their religious/cultural/ethnic background.
While the term's etymology might suggest that antisemitism is directed against all Semitic peoples, it has been used exclusively to refer to hostility toward Jews since its initial usage.
And even if you do not accept the standard definition of the word, it still makes no difference at all regarding the right of the Jewish people to the land of Israel.