British commentator Piers Morgan is urging President Trump Donald John TrumpOmar fires back at Trump over rally remarks: 'This is my country' Pelosi: Trump hurrying to fill SCOTUS seat so he can repeal ObamaCare Trump mocks Biden appearance, mask use ahead of first debate MORE to learn from the results of Tuesday's special Senate election in Alabama.

"If Trump doesn’t heed the gigantic alarm bells that went off last night, he’s a fool," Morgan wrote in a piece published in the Daily Mail.

"Momentum is everything in politics and the pendulum just swung dramatically back toward the Democrats."

ADVERTISEMENT

His comments come after Democrat Doug Jones on Tuesday defeated his GOP opponent, Roy Moore, in the Alabama race.

Jones is the first member of his party to win a Senate seat in the state since 1992.

Trump last week threw his full support behind Moore, who has been accused by multiple women of having inappropriate contact with them when they were teenagers and he was in his 30s.

Morgan in the op-ed called Moore an "unprecedentedly terrible candidate" and said Trump made a "catastrophically bad decision to support him."

"Alabama turned blue last night, driven largely by black men and women, and this astonishing turnaround may have potentially very far-reaching consequences for not just for 2018 but also the 2020 General Election," Morgan wrote.

"President Trump has only himself to blame. He should never have backed such a wretched horse. Roy Moore is a dumb, vile, racist, homophobic, anti-semitic, sexist Islamophobe."

Still, Morgan said Trump has achieved "considerable success" in delivering on some of his campaign promises, including growing the U.S. economy and curbing illegal immigration.

"This defeat will sting and hurt him but he may also help him in the long run, if he heeds the lessons from it," he wrote.

He urged Trump to stop listening to former White House chief strategist Stephen Bannon, who campaigned for Moore. He also said Trump must start being more "inclusive" and listen to other senior Republicans.

Trump should also stop his "below-the-belt attacks on Twitter," Morgan wrote.