I'm not going to defend Helen Thomas' comments. Any American who is going to argue that Israeli Jews should "get out" is going to have to be willing to advocate for the return of all the land west of the Mississippi River to Native Americans, since the provenance of the land on which America stands is far more legally dubious than that of the Jewish state. Thomas is now retiring, but Jon Chait makes a persuasive case for why she probably should have been gone long ago.
That said, it's worth noting that in American political discourse, as Matt Duss and Gabriel Winant have written, statements of a similar nature are completely appropriate when made about the Palestinians -- it's not, apparently, that bigotry is unacceptable, just the "wrong kind" of bigotry. This is the sort of incident that exposes the more tribal advocates on either side -- you cannot argue that there's something morally wrong about leaving Palestinians stateless and then argue that Israeli Jews should be left that way, just as you cannot argue that it is morally wrong to suggest Jews should "leave Israel" while asserting that Israel has the right to permanently displace the Palestinians. Or at least, you can't argue either of those points while claiming to adhere to any universal moral principle. Still, it's clear that one form of inconsistency here is infinitely more acceptable in Washington than the other.
-- A. Serwer