Donald Trump is picking up plenty of Republican endorsements as he settles into his new role as the party’s presumptive nominee. What they’re supporting, however, isn’t entirely clear.

A number of Trump’s signature positions are still almost wholly unique to him. Even among lawmakers who endorsed him earliest, there’s little vocal support for deporting all undocumented immigrants by force or banning Muslim entry into the United States, among other issues. This is to say nothing of his harsher rhetoric and shifting policy stances, which Republican politicians have bristled at having to address all year.

This creates a problem moving forward: How many of Trump’s new backers can credibly defend him once the Democratic attacks start in earnest?

Rep. Chris Collins of New York, the first House member to endorse Trump, illustrated the problem in an interview with the Buffalo News in which he backed off several of Trump’s most prominent policies.

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While Trump has promised at rally after rally to build a giant wall along the U.S.’s southern border and make Mexico pay for it – and to increase the wall’s height if Mexico refuses – Collins chose to take it as a metaphor.

view photo essay Political Theatre: The presidential campaign of Donald Trump “Make America Great Again.”

“I have called it a virtual wall,” he said. “Maybe we will be building a wall over some aspects of it – I don’t know.”

As for Trump’s plan to create a deportation force that would round up and remove all undocumented immigrants?

“I call it a rhetorical deportation of 12 million people,” Collins said.

How about the Muslim ban? Collins disagrees with that too, but said he believed “what [Trump] really meant” was that he’d institute a narrow restriction on Syrian refugees.

Unfortunately for Collins, that’s not what Trump meant. The candidate made it 100 percent clear from the outset that he wants “a complete shutdown of Muslims entering the United States,” and it took time just to clarify that he would exempt American citizens, military service members and some foreign leaders. He reaffirmed his support for the ban shortly after winning the nomination, despite some minor waffling last week, when he called the proposal “a suggestion.”

Collins isn’t the only one dealing with these issues. Rep. Renee Ellmers, who came out for Trump in March but is dovish on immigration reform, made clear this week that she isn’t willing to defend his calls for mass deportation. “Logistically, that is an impossibility,” she told Talking Points Memo when asked about his immigration plans.

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Trump’s day-to-day pronouncements are unpredictable and frequently controversial, giving additional heartburn to would-be surrogates. After Trump suggested this week he “would have no problem speaking to” North Korean dictator Kim Jong-un, several senators who support him squirmed through interviews, including one of his top backers.

“Well, you just have to be very careful about that,” Sen. Jeff Sessions, whose endorsement of Trump in February was a turning point for the campaign, told CNN when asked about Trump’s call for dialogue. Sessions added some tepid praise: “I think it’s unlikely that something good will come out of it, but to attempt something like that might be worth the effort.”

So far, politicians backing Trump have tried their best to downplay differences. Rep. Marsha Blackburn of Tennessee, for example, told “Hardball’s” Chris Matthews this month that she supported Trump because voters want “retirement security.”

But as Matthews pointed out, Blackburn’s position on “retirement security” is the opposite of Trump’s. She, along with virtually every Republican official, supports reducing entitlement spending and partially or completely privatizing programs to cut the long-term deficit. Trump has repeatedly pledged not to touch them.

To Blackburn, it was a case of “tomayto, tomahto”: “Well, I think sometimes you get into what did somebody say and what did people hear on that,” she responded.

To be fair, Trump’s own staff has given some mixed signals. Sam Clovis, national co-chair of Trump’s campaign, said at an event hosted by the fiscally hawkish Peter G. Peterson Foundation that Trump could “take a hard look” at entitlements once he was elected.

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With few elected officials able to consistently play a surrogate role for Trump, he’s had to rely on some less well-known picks who can go where others can’t.

Scottie Nell Hughes, a conservative activist who has become a fixture on cable news defending Trump, raised eyebrows in March when she argued “riots aren’t necessarily a bad thing” amid an uproar over Trump’s insinuation that his supporters would revolt if he lost the nomination at July’s convention.

Early this month, Hughes strongly defended Trump on “Hardball” after he reaffirmed his support for a ban on Muslims. “Why would he flip-flop now that he’s the candidate? That right there would show weakness,” she said.

Less than a week later, Hughes ably defended Trump on CNN from accusations that he was flip-flopping after he suggested he might abandon his proposal of massive tax cuts for the wealthy.

“I think you have to have a little bit of flexibility,” she said.

Juan Carlos Limón, a member of Trump’s diversity outreach team, has also taken some interesting turns. This month, he drew attention after suggesting on CNN Latino that voters are slow to support Trump because they are “very emotional.” He expanded on the remarks later in an interview with Univision anchor Jorge Ramos.

“Latinos, we have that blood,” Limón said. “We’re highly emotional. We may perceive different things in different ways. And when you get a person that is that abrupt, that direct, and maybe he … says things the wrong way, we get easily offended”

For conservatives iffy on Trump, there are still some easy rallying points. They don’t like Hillary Clinton, and they don’t want a liberal Supreme Court, an issue Trump addressed on Wednesday by releasing a list of possible judicial picks. But when it comes to the things that make Trump Trump and not just another Republican, it looks like he might be on his own.