NEW YORK — Fearing betrayal on a signature campaign issue, President Donald Trump’s loyalists are lashing out against his proposal to create a path to citizenship for nearly 2 million “Dreamer” immigrants.

Trump-aligned candidates from Nevada and Virginia rejected the notion outright. A loyal media ally, Breitbart News, attacked him as “Amnesty Don.” And outside groups that cheered the hardline rhetoric that dominated Trump’s campaign warned of fierce backlash against the president’s party in November’s midterm elections.

“There’s a real potential for disaster,” said Mark Krikorian, executive director of the far-right Center for Immigration Studies. “The president hasn’t sold out his voters yet. But I think it’s important that his supporters are making clear to him that they’re keeping an eye on him.”

The public scolding is aimed at a president who has changed course under pressure before.

His leadership may determine the fate of hundreds of thousands of young immigrants and whether his party can improve its standing among surging numbers of Hispanic voters.