Israel occupies and forces Palestinians to live in The West Bank and The Gaza Strip against their wishes. They are forced to live in terrible living conditions because the Israeli government has barred them from moving and settling into the rest of the country. Meanwhile, Israel continues to expand and build additional settlements for their own people in The West Bank, but they do not allow the Palestinians to do the same. They are essentially occupying the Palestinians solely because they are Palestinian. That, to me, is a form of apartheid. It is also a violation of International Law.
I think the rebuttal to this position would be that there are acts of violence occurring against Israel by Palestinians. However most Palestinians are not engaged in this "terrorism" at all. It is unjust and wrong to punish an entire ethnic/racial population based on the actions of a few. The Israeli's have taken a radically disproportional response by harming an entire population in response to trying to protect themselves from acts of violence.
I just believe in justice and proportional response. Millions of Americans and virtually every politician are Pro-Israel's occupation and suppression of the Palestinian people despite the clear humanitarian crisis it has created.