At the very beginning of the year, I pointed out that the long presidential primary, combined with the importance of Latino voters in the general election, put the Republican field in a prisoner's dilemma on immigration:

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. [...]

For what it's worth, I thought at the time that candidate would be Ted Cruz (though I wasn't confident enough to write that in the piece). So I was wrong about the main character. But man oh man, was I right about the plot.

Until now, the rest of the Republican field has managed to ignore Trump's immigration rhetoric, or at least avoid saying anything specific enough that could hurt them with Latinos in the general. But now that Trump has an actual policy platform on immigration, it appears that other candidates feel the need to stake out their own positions on the issue — and make it clear they're not softer on immigrants than Trump.

Latino voters might not be paying attention now, but sound bites last forever

For several weeks now, some liberal and immigrant groups have been pushing an idea some of them call the "Trump effect." The thesis of the Trump effect is that Trump is going to end up defining the Republican position on immigration for this election cycle.

The strong formulation of the Trump effect is that because Donald Trump is dominating media coverage of the Republican primary, his attitude toward immigrants and Mexico is going to be associated with the Republican Party in November 2016 in the minds of Latino voters — whether or not he's the nominee.

For what it's worth, I don't exactly agree with this formulation.

It's clear that many Latinos are paying attention to Trump who might not otherwise care about Republican primary politics. But I'm not convinced that the GOP couldn't hypothetically recover from this with the right nominee. If — to invent a ridiculous example — the Republican National Committee were to go back in time, return to the present with 1986-vintage Ronald Reagan, and nominate him to represent the party in 2016, I don't think the lingering memory of Trump would matter all that much.

The more moderate formulation of the Trump effect is that Trump's immigration rhetoric will force other candidates in the primary to move rightward on immigration, which will hurt whichever candidate ends up winning the nomination.

I think this is likely — and it's similar to what I wrote way back in January:

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.

But other Republicans — with the important exception of Marco Rubio, who openly fact-checked Trump during the first televised Republican debate — managed to avoid engaging directly with Trump on immigration for a surprisingly long time. As a result, they managed to avoid saying anything that could last as long as "self-deportation" would in the general. But it appears that era has passed.

Scott Walker can't occupy two immigration positions at once forever

It's probably not surprising that the first competitor to succumb to the allure of Trump was Scott Walker. Walker was clearly considering positioning himself as the immigration hard-liner in the race, an alternative to Marco Rubio and Jeb Bush; he was flirting with restrictionism of legal immigration before Trump enthusiastically embraced it. But Walker also had this repeated problem where news stories kept coming out about how, in private, he was telling Republican elites what he thought they wanted to hear: that he supported legalization of unauthorized immigrants, or that he didn't want to cut legal immigration.

In other words, Walker was clearly trying to keep up appearances with the Republican base in the primary, without alienating anyone who might want him to take a more conciliatory approach in the general election.

Walker still hasn't gotten his messaging down on immigration. On Monday, MSNBC's Kasie Hunt asked Walker whether he (like Trump) believes the US should get rid of birthright citizenship; Walker said "yes"; and then Walker's campaign followed it up with a word-salad clarification that (if I'm reading it correctly) says that if we do what Scott Walker wants, we won't even need to change birthright citizenship:

VIDEO: Scott Walker tells me he thinks birthright citizenship should be ended. http://t.co/QLuUeXHCOv Spox: pic.twitter.com/qPXiPZ144o — Kasie Hunt (@kasie) August 17, 2015

But in one respect, Scott Walker is perfectly clear: He agrees with Donald Trump's immigration plan, and in fact it is "very similar" to Walker's own.

The full quotation from Walker is, "The things I've heard are very similar to the things I've mentioned," which isn't quite as sound-bitable as, "The answer is self-deportation." But it's definitely a clear association of Walker with the set of policies Trump is calling for, which includes mass deportation (and, possibly, the expulsion of millions of US citizens as well).

It's hard to believe that Walker, after co-signing Trump's policy so quickly after it came out, won't continue to talk up his own hard-line stances on immigration. So could current second-place candidate Ben Carson, who is taking a tour of "smuggling routes" in Arizona later this week. So could current third-place candidate Ted Cruz.

Right now, it is not at all clear who will be the Republican nominee for president. Jeb Bush and Marco Rubio might not feel a tremendous amount of pressure to move to the right on immigration to meet Trump, but that's because neither of them is doing well enough in the polls to earn much attention. (Walker hasn't been doing impressively himself.) So it's hard to know whether the candidates who get sucked into Trump's orbit now will end up regretting it next year. But saying that your immigration plan is very similar to Donald Trump's is probably the sort of statement that will, at some point in the general election, be regretted.

VIDEO: Donald Trump speaks on immigration