DENVER — It’s become even clearer thanks to Wisconsin Gov. Scott Walker: Immigration is the banana peel of 2016 Republican Presidential politics.

Just ask Florida Sen. Marco Rubio. He stepped up as a Senate leader on immigration only to slip and fall in a Tea Party ruckus over the issue. In a moment of candor, Rubio remembered the months of trying to get back up as “a real trial for me.” Others, too, have shifted on the matter.

Now it’s oops for Walker.

In 2013, Walker said offering immigrants in the country a way to become citizens “makes sense.” Early this month, however, he said he no longer supports “amnesty.”

Complicating that switch, Walker recently discussed immigration with New Hampshire party leaders. One of them, State Chair Jennifer Horn, says that he favored legal status — a position many conservatives equate with “amnesty.” Worse for Walker, The Wall Street Journal reported that he actually said he favored a path to citizenship, though Horn denies Walker said that.

Even former Florida Gov. Jeb Bush, who has a strong voice — and a book — on immigration, has wiggled.

Rubio and Walker are not alone in embracing an immigration overhaul at some point. But doing so raises the specter of “amnesty” in the minds of those who want people unlawfully in the country to be given no relief from the threat of deportation.

“All the candidates have mixed statements — they have statements that seem to support amnesty and they all have ones that seem to oppose it,” said Roy Beck, Executive Director of Numbers USA, which seeks to reduce immigration. “They’re torn between the big-money people who gain from high immigration and the voters who oppose it.”

Luis Alvarado, a California-based GOP strategist, said most Republican officials privately acknowledge that the country has to legalize the status of people who are here unlawfully while also bolstering border security.

“They believe that no one in their conscious mind can deport 11 million people from this country,” Alvarado said. “But, politically, they have to play word games to be elected in the primary.”

Among the potential 2016 hopefuls:

—Bush has said he won’t shrink from his support for giving legal status to many in the country illegally. But his 2013 book outlining that stance marks a departure from an earlier position that envisaged eventual citizenship.

—Before he shied away from the issue, Rubio co-wrote a bill with a path to citizenship that passed the Senate and failed in the House. He now says the bill was the wrong approach and that the focus should be on border security, a standard GOP position that leaves questions about deportation unanswered.

—Kentucky Sen. Rand Paul voted against Rubio’s bill but says the millions of people in the country illegally can’t all be sent home.

—New Jersey Gov. Chris Christie once supported an overhaul; now he won’t say where he stands. His state, though, is backing other Republican-led states in a suit against President Barack Obama’s orders deferring deportation for some immigrants.

—Former Texas Gov. Rick Perry is talking tougher on immigration than when he called his 2012 campaign rivals heartless if they opposed a law that lets some children of undocumented immigrants pay in-state tuition at public colleges. Even so, he says the U.S. will not deport all people here illegally.

Texas Sen. Ted Cruz, the only declared candidate so far, has kept a fairly consistent tough line on the issue.

Matt Schlapp, Chairman of the American Conservative Union, said “the ground has shifted” on the issue for two reasons — an influx of Central American youth crossing the border illegally last summer overwhelmed federal officials, and Obama’s unilateral acts to shield some immigrants from deportation made it politically impossible for a Republican to embrace a pathway to citizenship.

“You’ve got to cut these guys some slack,” Schlapp said of the presidential hopefuls and their wavering words.

But Frank Sharry of America’s Voice, which supports an overhaul, said some of Bush’s rivals are “going to be accused of flip-flopping and that’s going to become a character issue” playing into Bush’s hands.

The wide-open nature of the GOP race also brings to light a tension between what some Republican fundraisers want — an overhaul with a legal path — and what conservative primary voters wish for.

Spencer Zwick, Finance Chairman for 2012 Republican nominee Mitt Romney, is one donor who has said he will only support candidates who favor such an overhaul. At this early stage, the competition for dollars has been more intense than the competition for votes.

“Once they get into the debates, this all changes,” Beck of Numbers USA predicted, meaning he expects the candidates to rally behind a harder line.

(NICHOLAS RICCARDI)