Reports of a deal between Donald Trump and Democratic leaders to protect undocumented migrants who arrived in the US as children have generated ripples of doubt among the president’s supporters, some of whom were alarmed by Trump’s statement on Thursday that “a wall will come later”.

Trump’s campaign promise to build a wall along the US border with Mexico was a main selling point that led conservative elected officials such as Justin Simmons, a state representative in Pennsylvania, to throw their support behind the real-estate developer turned politician.

For Simmons and others, reports that Trump had cut some sort of deal on immigration – one that apparently did not include funding for a border wall – over a cozy White House dinner with House minority leader Nancy Pelosi and Senate minority leader Chuck Schumer raised a red flag.

“I’m actually disappointed in that deal by the president,” Simmons said. “I think a lot of people are starting to wonder if he’s going soft on that issue. I do not agree with that deal. I think had the wall been a part of the deal, I’d be fine with it, but I’m not OK with it at all.”

Before flying to Florida on Thursday to review damage from Hurricane Irma, Trump described his agreement with the Democrats as an exchange of concessions on border security spending for his willingness to sign legislation protecting the 670,000 recipients of the Obama-era Deferred Action on Childhood Arrivals program, or Daca.

“Subject to getting massive border control, we’re working on a plan for Daca. People want to see that happen,” Trump said, adding: “The wall will come later. We’re right now renovating large sections of wall.”

Immigration hawks interviewed by the Guardian on Thursday in a swing district in Pennsylvania that voted for Trump last November raised an eyebrow at the deal as the president described it.

Dean Browning, chairman of the immigration committee of the Lehigh Valley Tea Party, said “the wall has to come first” before any move to protect Dreamers, as Daca recipients are known.

“Before we have any settlement of the Dreamer situation, we need to take steps to make sure that we seal our border, which means build the wall,” Browning said. “As long as any deal includes funding for the wall, then I’m fine with it.”

Trump did not appear to be facing a fully-fledged mutiny, yet, over his seeming willingness to put the border wall project on the back burner. A prominent Trump supporter in Pennsylvania, US representative Lou Barletta, an immigration hard-liner who cheered the president’s Muslim travel ban and repeal of Daca, declined to criticize Trump on the issue on Thursday.

“I have no idea what happened in that room last night, so I’m not going to even speculate,” Barletta told reporters.

Browning and others said that they had no problem with the president working with Democrats, if that was the only way forward.

“The president was elected to make progress and he was elected specifically for saying he was going to build the wall,” said Browning. “If the Republicans will not cooperate, then he needs to put together whatever coalition to accomplish that.”

Simmons said: “I understand the president’s frustration with his own party. I understand exactly what he’s doing. I’m not really OK with it, but I understand it.”

Both even conservative political activists particularly focused on immigration said there was room in the US on “humanitarian” grounds for Dreamers – a view that if polls are correct, reflects the opinion of a majority of Americans.

And if Trump really does put the wall second? “I would not be happy with him,” Browning said.

“But I’m not going to suddenly say I no longer support Donald Trump, and wish we had Hillary Clinton. I would be extremely disappointed in him – but that’s not a deal-breaker.”