Here's the fundamental problem that President Obama's executive actions on immigration pose for Republican presidential candidates in 2015, during the long run-up to the first primaries. Many conservative activists will be working hard to get candidates to take a hard line against any form of "amnesty" for unauthorized immigrants. But if the eventual GOP nominee is on the record promising to get rid of President Obama's relief programs for the unauthorized, he's going to be at a massive disadvantage with Latino voters.

collectively, they're better off not saying anything too specific. individually, there's a huge benefit to doing just that

Presidential campaigns tend to solve problems like this by running quickly to the center in the general election. But when it comes to immigration, that's just not going to work. Neither conservative immigration hawks nor liberal immigrant activists are willing to let a candidate walk away from a hardline position.

This puts GOP candidates in an epic prisoner's dilemma that could last all the way through 2015. Collectively, they're better off not saying anything about immigration that's specific enough to be a problem for them later on. But individually, there's a huge short-term benefit for the first candidate who can turn immigration to his advantage in the primary — and candidates will be under tremendous pressure from activists on both sides of the issue to take a stand.

A hard line on immigration is a massive liability in the general election

For many Republican primary voters, opposition to unauthorized immigrants just isn't a high priority. But is a priority for core conservative organizers. Researcher Vanessa Williamson studied activists in Massachusetts during the rise of the Tea Party and the campaign that got Scott Brown elected to the US Senate in 2010. She found that even though Massachusetts was far from the US/Mexico border, attitudes about immigration were surprisingly strong: the organizer of the Greater Boston Tea Party told Williamson that news from the border made her "want to go stand at the border with her gun." In Williamson's view, immigration is an important symbolic issue for conservative activists: they're motivated by the sense that the country they're living in now isn't the country they grew up in (and that it's changed for the worse), and the increasing diversity of much of America thanks to immigration is a very visible signal of that change. Obama's actions as president — up to and including his recent executive actions — have confirmed their worst suspicions.

The problem is that, when it comes to winning votes in 2016, a hard line on immigration doesn't win votes on the margin, but it does lose them. Obama's executive actions didn't do much to affect white voters' opinion of his immigration record — how whites feel about "Obamnesty" is more about their existing opinions about Obama than about immigration. But it was a tremendous deal for Latino voters — including registered Republicans. Three-quarters of Latino Republicans support Obama's new program, and 60 percent of Latino Republicans oppose any effort by the GOP Congress to block it from going into effect.

In a presidential election year, the Latino vote matters: by 2016, they'll represent 15 percent or more of eligible voters in at least three key swing states. Most Republican elites feel they need to win over Latino voters in the long term, and many (including the Republican National Committee) believe that the first step to doing that is to stop alienating them on immigration.

The tipping point: committing to a specific policy position

This isn't to say that Republicans are doomed if they say anything about immigration. Jeb Bush's recent refusal to attend an event organized by Iowa immigration hardliner Steve King, for example, should definitely be interpreted as a statement that his immigration position differs from King's. Other potential Republican candidates might want to attack Bush over the snub, as a way of shoring up their hardline bona fides. But that's way too far in the weeds for most voters to care about now or later.

The trouble for candidates is avoiding the tipping point when signaling on immigration becomes something more explicit — something a candidate could be held to.

We've already seen how that happens. In the second half of 2011, eventual nominee Mitt Romney launched two different attacks on opponents Rick Perry and Newt Gingrich by running to their right on the issue. To contrast his position with theirs, Romney needed to have a plan of his own for unauthorized immigrants — which he put forward during a January 2012 debate as "self-deportation," or making it so difficult to live in the US without immigration status that immigrants would leave en masse on their own.

Latino voters weren't interested in the Republican primary. But that phrase came to define his candidacy on the issue — it was far more durable than anything he said about immigration during the general election. The result? Romney did an unprecedentedly bad job among Latino voters, winning only 27 percent of the vote. That's not something a Republican presidential candidate can afford to repeat in 2016.

Etch-A-Sketching didn't work on immigration in 2012, and it won't work in 2016

It's long been accepted that candidates will run to the wing of their party to appeal to primary voters, then run to the center to appeal to the public. In 2012, Romney adviser Eric Fehrnstrom made the mistake of saying out loud what everyone believed: "Everything changes. It’s almost like an Etch A Sketch. You can kind of shake it up and restart all over again."

The reasoning behind that is that most voters outside the party's base haven't been paying attention to the primary, and aren't terribly inclined to do research to get caught up. Instead, they'll define the candidate based on what he says when they are paying attention, during the final weeks of the campaign.

Activists on the other side of an issue could choose to embrace the candidate's more centrist general-election position. But that's not what immigrant activists do. They take the explicit positions a candidate took in the primary more seriously than the possibility that the candidate might moderate his views once in office.

When Romney tried to Etch-a-Sketch on immigration — emphasizing his support for high-skilled immigration, staying silent on President Obama's Deferred Action for Childhood Arrivals program (and then quickly flip-flopping on whether or not he would get rid of it), and saying nothing about the "self-deportation" comments that had defined him in the primary election — the Obama campaign and immigrant groups stepped in to explain "self-deportation" to Latino voters instead. Romney's pitiful performance among Latinos wasn't because he hadn't tried to moderate his positions in the general election — it was because his statements in the primary had made it impossible for him to do so.

Unlike Romney, Jeb Bush has a history as an immigration reformer. And he's starting the 2016 campaign with a level of trust — or at least hope — among immigration advocates like Frank Sharry of America's Voice, who are hoping he'll stand his ground in support of reform throughout the primary season. But Sharry's already making it clear that if Bush moves to the right on immigration in 2015, that's going to be what defines him in 2016 — and what gets Etch-a-Sketched away, instead, will be his pro-immigrant record of the past. Asked what would happen if Bush ran to the right on immigration in 2015 and then ran to the center as the nominee, Sharry says, "I don't think we'd give him a pass."

Even if pro-reform advocates did give a candidate a "pass," conservative advocates would not. Williamson says that after Scott Brown got the GOP's nomination for Senate, activists "knew that he was going to represent all of Massachusetts. And so they knew that they were going to have to follow up constantly to make sure that their positions were the positions he was held to."

The prisoners' dilemma: stay vague on immigration, or use it as an intra-party wedge?

That means that it's best for the eventual nominee not to say anything during the primary that can come back to haunt him in the general election. So collectively, Republican presidential candidates have an incentive to avoid the issue. They can't go an entire year without mentioning immigration at all, but they can stick to tough-sounding rhetoric, and controversies like the Steve King event — and avoid making any concrete statements about policy.

"you're going to have a very hard time appealing to the tea party if you don't follow through on the substance"

But in a long pre-primary season, candidates struggle to distinguish themselves from each other — and frontrunners scramble to kneecap any potential challengers before they can gain momentum. So there are plenty of opportunities for short-term gain by using immigration (or other issues) as an intra-party wedge. That's especially true since, as Williamson points out, Tea Party organizers are less interested in finding and championing a single "Tea Party candidate" than in doing as much as they can to ensure the eventual nominee is someone who shares their views — by pressuring as many candidates as they can trust. In 2012, "of course they didn't like Mitt Romney. But they wanted him to hold their positions. They were willing to organize to make that happen."

To use immigration as a short-term play for the Tea Party, though, candidates have to get specific about policy. Williamson stresses that the organizers she studied are "very savvy organizers" who push hard for explicit policy promises; "they're not going to be fooled" by tough-sounding rhetoric that doesn't say anything about what a candidate would actually do, or that spins bipartisan proposals like the Senate's immigration reform bill as conservative victories. "You're going to have a very hard time appealing to the tea party if you don't follow through on the substance about immigration," she warns.

That's what happened to Mitt Romney in 2011. Romney's statements on immigration started out vague. But to use the issue effectively against Perry, and then against Gingrich, he had to be clearer about how his position was different — which led him into endorsing "self-deportation."

Both immigrant activists and Tea Party conservatives will be fighting to get candidates on the record

Here, too, Tea Party activists and immigrant activists are working in parallel: both are working to get candidates on the record declaring what they'd actually do on immigration if elected. In 2012, an immigrant activist was the first person to get Romney to explicitly say he'd veto a bill to allow unauthorized-immigrant college students to get legal status and apply for citizenship.

And they were already working on the 2016 presidential candidates in 2014, shadowing both potential Republican presidential candidates and potential Democratic ones to get them on the record regarding executive action.

That effort is only going to intensify in 2015. Candidates will spend the year hearing "Do you want to deport my parents?" at public events; behind closed doors, they'll be working to woo activists who want an answer to the same question. If they want to make it through the primary without saying anything that could be used against them in the general election, they're going to have to ignore both of those groups for a very long time.