Saying the Palestinians are "an invented people" is like calling the Dallas Cowboys "an invented football team". Of course they are—exactly like every other national group in the world. Does Newt Gingrich think some people have a particular nationality stamped into their genome? And does he also search for a big black line painted on the ground whenever he's near a national border?
Gingrich isn't concerned about making sense, of course; his purpose is just to sufficiently delegitimize the Palestinians that the destruction of their homes and theft of their land will become less objectionable. He wants to make the West Bank and Gaza safe for people who have an organic, indisputably legitimate claim to it: Russian Jews, say, or Peruvian Indians who've converted to Judaism.
(Funny how only Israeli settlers can create "facts on the ground," isn't it? No matter how long a Palestinian family has lived in the same house, they'll never be anything more than squatters on someone else's land.)
BONUS: Proving once again that Democrats are some of the best Republicans around, Obama attempts to outflank Gingrich et al from the right on Israel.