WASHINGTON — When President Trump signed a $1.1 trillion spending bill on Friday, he zeroed in on a tiny sliver of it, suggesting that he might disregard $20 million in funding for loan subsidies and other aid to historically black universities.

Two nights later, after a storm of criticism, the White House walked back the threat in a statement that declared the president’s “unwavering support” for such schools.

But the two days in between left some African-American educators feeling used, many black politicians enraged and some demanding that Mr. Trump back his “unwavering support” with a show of budgetary support. It also, once again, revealed a White House where one team does not necessarily know what another team is up to.

“I worked to make sure there was clarity because I observed that there was feedback and some were misconstruing the signing statement,” Omarosa Manigault, a close aide to Mr. Trump, said in an interview on Monday. Ms. Manigault headed Mr. Trump’s outreach to black voters during his presidential campaign and had publicly promised that his budget would protect historically black colleges and universities.