The Republican field for 2012 is beginning to stretch its legs. Not surprisingly, presidential hopefuls have started to define themselves by what they are not: Barack Obama.

There are predictable swipes at Obama’s health care reform plan, his deficit spending, his climate-related regulations and his obsequious displays before foreign potentates. If you are looking to serve up red meat to the Republican troops, these are easy and effective stand-bys. In recent months, however, a new issue has emerged with which Republican contenders are trying to distinguish themselves: West Bank settlements.

In August, former Arkansas governor and television talk-show host Mike Huckabee made a high-profile visit to the West Bank. He compared efforts to restrict the growth of Jewish settlements to Jim Crow-era segregation: “To tell Jewish people they can’t live in certain neighborhoods is really to deny them not just their neighborhood, it’s to deny them their basic sense of liberty.”

More recently, Sarah Palin offered a more curious rationale for settlement expansion: “That population of Israel is going to grow. More and more Jewish people will be flocking to Israel in the days and weeks and months ahead. And I don’t think that the Obama administration has any right to tell Israel that the Jewish settlements cannot expand.”

In standing up to Obama on settlements, Palin and Huckabee have staked out positions significantly to the right of past Republican presidents. George W. Bush’s basic policy was: Build up, but don’t build out, and don’t permit illegal outposts. (Ronald Reagan and George H.W. Bush were even more hostile to settlements.) I don’t recall Palin and Huckabee complaining about the Bush White House’s stance on the issue.

It’s worth noting that other leading Republicans have found a way to take issue with the Obama administration’s stance on settlements without climbing out on the limb that Huckabee and Palin have. The House minority whip, Rep. Eric Cantor, has called the settlement issue “a distraction” from the bigger threat posed by Iran. “The status of the settlement blocks is something to be resolved in future agreements; it is not something we should begin pressuring Israel on now, when there really have not been adequate steps taken by the Arab states and the Palestinians,” Cantor told The Jerusalem Post.

So what explains the zeal on settlements from Huckabee and Palin? It could be that they sincerely believe what they say: America has no right to tell Israelis where to live. One can speculate that their religious convictions play a role shaping their views on this issue. Or maybe Huckabee and Palin simply don’t place much hope in the prospects for a two-state solution.

But their focus on settlements could also be seen as a calculated political move to distinguish themselves from the Republican pack. With virtually the entire Congress — Democrats and Republicans — reliably lining up to support Israel on the easy stuff, you can’t make your mark unless you take on the hard stuff and go further than anyone else.

And the settlement issue, of course, has particular appeal to Christian conservatives who believe God gave Israel to the Jewish people. Saying that settlements are Israel’s right is a way of telling Christian Zionists, “I’m with you.”

Some have argued that Palin’s remarks about settlements had an end-is-nigh feel, with prominent liberal blogger Spencer Ackerman suggesting that her words “sounded like some kind of dogwhistle to Christian Zionists, a cohort that promotes unconditional American support to Israel in order to bring about the end of the world and the return of Jesus Christ to earth.” (It’s an imposed reading, one not supported by Palin’s actual words. Either Palin is a simpleton, as her critics say, or she is crafty and sends intricately coded messages to her supporters. Both things can’t be true simultaneously.)

So what’s driving Palin and Huckabee — conviction or political expediency? The answer is probably at least a bit of both. I don’t doubt that they have both arrived at their positions on settlements in good faith, though it’s unlikely they have devoted serious study to 42 years of American foreign policy on the issue. And, in any case, they likely see the settlement issue as a cost-free way of scoring political points against an incumbent president who is seen by many as the least friendly president toward Israel since Jimmy Carter.

But I’d advise them to be careful.

Every Democratic candidate in the run-up to 2008 ran as far away from George W. Bush as they could. But such exercises in zagging when the incumbent administration is zigging can be dangerous: It cost candidate Obama nothing to say he was the anti-Bush on a range of issues. It’s not so easy now that he is governing and is actually carrying forward key Bush policies on Guantanamo, Iraq, tax relief for many American families and so on. Not surprisingly, Obama’s friends are often bitterly disappointed by these departures from his campaign promises.

On the campaign trail, you can say whatever you want. But people remember. And words, in the end, have consequences.

Noam Neusner is the principal of Neusner Communications, LLC. He served as a speechwriter and Jewish liaison for President George W. Bush.