Donald Trump supporters are lashing out at the president-elect for backing down from prosecuting Hillary Clinton over her use of a private email server.
His team said he would not keep his campaign pledge to try to have her jailed, and Mr Trump later said it would be too divisive to go ahead with.
The FBI cleared her of any criminality but chants of "lock her up" became a rallying cry at his campaign events.
Conservatives seized on the news as a "betrayal" and a "broken promise".
Redstate.com said that a failure to appoint a special prosecutor, as Mr Trump promised, would reveal the "very real fact that the candidate is not who he claimed to be".
The right-wing Breitbart News Network, one of the Manhattan billionaire's most loyal supporters, denounced the climb-down as a "broken promise".
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Conservative commentator Ann Coulter tweeted her reaction to the news, saying: "Whoa! I thought we elected @realDonaldTrump president. Did we make him the FBI, & DOJ? His job is pick those guys, not do their jobs."
She later followed up to say that: "No president shld be blocking investigators from doing their jobs. #EqualUnderLaw"
The right-leaning legal organisation Judicial Watch said it was "a betrayal of his promise to the American people to 'drain the swamp' of out-of-control corruption in Washington".
Reality check: Jon Sopel, BBC News North America Editor
Remember crooked Hillary? The most corrupt politician ever, whose email scandal would be as big - if not bigger - than Watergate?
The butt of all those full-throated chants at Trump rallies, "lock her up, lock her up"?
And who could forget the memorable exchange in the second presidential debate, when Donald Trump promised to appoint a special prosecutor.
But now all that is gone, just some overheated campaign rhetoric that is being shelved, if you listen to his spokeswoman, Kellyanne Conway and close confidante, Rudy Giuliani.
This is part reality check: there is so much to do in the first 100 days, do you want to be bogged down in something as controversial as this?
And it's partly that the job's been done - if the language during the campaign was about discrediting Hillary Clinton in the eyes of enough of the electorate to get Mr Trump elected, then, well, it's mission accomplished.
During the campaign, Mr Trump repeatedly vowed to launch new prosecutions against his "crooked" opponent, whom he described as the most corrupt candidate in history.
The first signs since the election that he was not so full-throated in his conviction came in an interview a week ago in which he said the Clintons were "good people".
Then on Tuesday morning, his spokeswoman Kellyanne Conway said there would be no further investigation into Mrs Clinton's emails, in order to help her "heal".
A few hours later, Mr Trump told the New York Times that a fresh inquiry was not off the table but unlikely because it would be divisive.
"I want to move forward," he said. "I don't want to move back. I don't want to hurt the Clintons, I really don't."
Mrs Clinton had a private email server while secretary of state, actions the FBI said were careless but not criminal.
In the same New York Times interview, Mr Trump distanced himself from white nationalists who performed Nazi salutes at a conference in Washington.
He also said:
- Son-in-law Jared Kushner - a real estate heir who has no experience of diplomacy - could help forge peace between Israel and Palestinians
- The US should not be a "nation-builder" in the world
- He could run his business and the country both "perfectly"
- There were no conflicts of interest because he was president and the law was on his side
- There is some "connectivity" between human activity and climate change
Mr Trump took a break from assembling his new administration to fly to Florida on Tuesday evening for Thanksgiving.
He will be inaugurated on 20 January.