Which campaign would that be? Israel wasn’t founded legitimately in the first place. The UNGA resolution recommending the Partition Plan was opposed by Britain in particular (as the country with the Mandate to govern Palestine) and the UNSC in general, because it violated the rights of the Palestinian majority; the US pressured various members into changing their vote to push it through; but it had no legal weight as the UNGA did not and does not have the power to create states. It was never anything more than a recommendation, and in fact it was never implemented.
Ben Gurion & the other Zionists active in Palestine at the time obviously didn’t want a one-state solution because they were in the minority and would have lost their state in the first election. Even with all the post-war Jewish immigrants, Palestinian Arabs were still a significant majority. Britain, as an experienced colonial administrator, objected to Partition because it violated the terms of the Balfour Declaration (which explicitly guaranteed the rights of the Arab inhabitants of Palestine and only promised the Jews a homeland, not a state). Britain gets bad press for trying to prevent the immigration of Holocaust victims, but I think they and the UNSC saw very clearly that the formation of a Jewish state would immediately lead to a war with the Arab League, as it was essentially a hostile occupation; and of course, that’s exactly what happened.
After WWII and with Stalin on their hands and the Berlin Blockade about to start, Britain didn’t have the resources to manage a difficult situation in Palestine and ended the Mandate on 14 May 1948. The State of Israel was unilaterally declared the next day, and the Arab League promptly and justifiably declared war. And the last 65 years have been testimony to what a disastrous mess that was.
The radical Palestinians (Hamas is becoming mainstream) are thus historically quite correct. The land belongs to them, not to Israel. However, I doubt if anyone would have begrudged the Jews a homeland after the Holocaust, and Abbas (Fatah) is moderate and very willing to accept a two-state solution if the settlements are stopped.
The problem now is not Palestine but the Revisionist Zionists in control of Likud; they believe that they are historically entitled to the Biblical boundaries which supposedly go up to the Jordan, they’ve fragmented the West Bank into Bantustans, they violate every single ceasefire and then manage to accuse the Palestinians of starting it, and of course they feed the aspirations of more hardline Palestinians. (This last round in Gaza started when the IDF shot a 12-year-old Palestinian boy, but all you will hear about in the US press is rockets. 28 Israelis have been killed by Hamas rockets in 9 years, compared to hundreds of Palestinians. That’s still 28 Israelis too many, but the notion that Israel is in permanent danger from these vicious terrorists is absolute garbage.)
So I would say that if the US really wants to secure the future of Israel instead of just pandering to the internal Jewish lobby, the best thing they could do would be to stop vetoing, recuse themselves (the US is not an honest broker here) and allow someone else to force Israel to genuine terms while Abbas is influential. (If that means a few Israeli politicians end up going on trial in the ICC for war crimes, too bad. They deserve it.) Leave it much longer and Hamas and Islamic Jihad will become dominant, and with the Arab Spring and much more unity amongst the Arab countries, I think the end of Israel isn’t far off.
Put it this way; for most people, including younger liberal Jews, Israel is becoming more trouble than it’s worth, the Arab world is on the ascendant again (look at Dubai & Qatar for example) and are far more desirable allies than Israel, and ultimately, even if they’re willing to ignore Arab sentiment, I doubt if the US will take on China over this. China backs statehood for Palestine, in terms of international influence, they’re going to pull ahead of the US sooner rather than later, and nobody with any wits to spare takes on the Chinese militarily. They wrote the book.