President Donald Trump called Omarosa Manigault Newman a lowlife and a dog in response to allegations she made against him.

The approach appears to be backfiring.

Omarosa is on a publicity tour for her new book recounting her time in the Trump administration.

But she has already contradicted herself and lacks credibility as she makes bombshell allegations that Trump is a vocal racist.

Trump could have ignored the allegations and let it blow over — but he did not and has instead raised Omarosa's profile.

President Donald Trump called Omarosa Manigault Newman, his former White House aide and reality-TV colleague, a lowlife and a dog in response her calling him racist — a strategy that appears to be backfiring on him.

Omarosa, on a publicity tour for her new book, has emerged from her brief stint in Trump's White House as a Trump enemy after years of publicly praising him and working for his campaign and administration.

Omarosa's promotional efforts are now wildly successful thanks to the president's hot rhetoric. If Trump set out to silence her rumors, his outbursts have done just the opposite.

Armed with tapes of private conversations, she's described Trump as a racist with a history of using vile slurs against black people.

But Omarosa doesn't exactly command credibility. For example, in her book she says she spoke with a source who had heard a tape of Trump using racial slurs.

But in a recent NPR interview she said she heard the tape herself, seeming to contradict what she wrote in the book.

The Republican pollster Frank Luntz also pushed back on details from the book around the alleged tape.

"I'm in @Omarosa's book on page 149," Luntz tweeted. "She claims to have heard from someone who heard from me that I heard Trump use the N-word. Not only is this flat-out false (I've never heard such a thing), but Omarosa didn't even make an effort to call or email me to verify. Very shoddy work."

But Trump, by constantly bringing up Omarosa, elevated these allegations from mere rumors to topics of national conversation, and that hasn't gone very well for him.

Backfire

The two at a church service in Detroit. Thomson Reuters

Trump's response to Omarosa's allegations, which could have been denied and swept under the rug, looks to have exacerbated the situation and given the story new life.

After a barrage of questions about the book during Tuesday's press briefing, the White House press secretary, Sarah Huckabee Sanders, said she "can't guarantee" that a recording of Trump saying the N-word wouldn't emerge.

Even Geraldo Rivera, a longtime Trump defender, thought the president's tirade against Omarosa went too far.

Additionally, NPR reported on Tuesday that Trump's campaign filed a complaint accusing Omarosa of violating a 2016 nondisclosure agreement with her book tour, meaning this could now play out over a lengthy arbitration process, resurfacing again and again.

But, lucky for Trump, despite his considerable efforts to keep Omarosa's name in the news, her book has not emerged as the best-seller that previous inside accounts of the Trump administration have been.

Also, Omarosa may have opened herself up to legal trouble after she said she recorded audio in the White House Situation Room.

In any case, sources close to Trump told the news website Axios that the president was advised to hold his tongue and let the controversy blow over but simply could not help himself.