He is factually correct. Gingrich said the Palestinians are an “invented” people who seek to destroy Israel. That's almost as self-evident as "X=X."
There has never been a Palestinian state or people. Can you name the last Palestinian capitol? How about the last Palestinian President, Prime Minister, King or other head of State? How about any famous Palestinian from before Israel was attacked in 1948?
Sure, you hear about "the Palestinians" all the time but have you ever asked "who the heck are they?" They are almost all exiles and their descendants. Most are Jordanian. Most of the remainder are Egyptian (Do we yet have a more iconic "Palestinian" that Arafat? - He's Egyptian. You may have failed to notice that.) Only a very small few "Palestinians" have any ancestral ties to Israeli land, or indeed to the land they live in now.
Those very few who left what is now Israel were not expelled. Their cousins are Israelis. Some are or have been members of the Israeli legislature, having far more rights than do Arab people anywhere else in all of the Middle East. The "expelled Palestinians" in fact left for one or both of two reasons: The Arab League told them to, so as to avoid the peril of impending Arab invasion and/or they simply couldn't stomach the idea of living among so many Jews. It's pretty obvious why some people would want them to be recognized as a nation-State, isn't it?
For the sarcasm-impaired, by "some people," of course, I mean the insane, the ignorant and/or the evil. I can't imagine anyone else thinking it's a good idea.