WASHINGTON: US president Donald Trump on Thursday backed the Republican candidate for Ohio governor over an attack ad featuring a rival's estranged mother, whose husband was charged with raping the Democratic candidate as a child.
Trump said the ad by Vivek Ramaswamy on his Democratic rival Amy Acton was "so good" and accused the media of a coordinated attack to undermine the Republican's chances.
Ramaswamy has faced a firestorm of criticism over the ad featuring Acton's mother, who remained married to the man who the candidate says sexually abused her for years, and now accuses Acton of being a liar.
"Vivek should keep it up, and let everyone listen to the mother of a defective, dishonest, and incapable Candidate, explain how the daughter is a DISASTER who, uncontrollably, lies, cheats, and steals!" Trump wrote on his Truth Social network.
Trump, 80, added: "If my mother, the legendary Mary MacLeod Trump, said anything bad about me, the Fake News would play it up".
The US president doubled down on his justifications when quizzed by reporters later, saying that Acton was "fair game" and that he was unaware of the abuse allegations.
"I know nothing about it," Trump said. "If what the mother said about the daugthter is half right, she has no right to be running for the governor of Ohio," he said.
The ad comes amid increasingly bitter rhetoric ahead of the Nov 3 US midterms, when a number of governors and senators plus all members of the US House of Representatives and dozens of US senators are up for election.
Ramaswamy, a billionaire biotech entrepreneur who ran in the 2024 Republican presidential primaries against Trump, is facing off against Acton, a medical doctor by training and former state health department director, in the race to be Ohio's next governor.
In the Ramaswamy ad, Arthur says her daughter has "lied her entire life".
Arthur's husband fled before he could be tried on the sexual assault charges and is now dead. Acton, 60, said she had not seen Arthur since 1978.
On Tuesday, Acton issued a statement saying she and her brother "endured abuse, hunger, and neglect" as children.
Acton's campaign also ran a video featuring her brother Phil Stearns, who said: "She was 11 and 12 years old, and to think that that's somehow a talking point. Shame on Vivek".
Democrats and some Republicans have criticised the ad.
Current Ohio governor Mike DeWine, a Republican who has endorsed Ramaswamy to succeed him, said the advertisement was "wrong" and said it should be taken down.
Trump dismissed DeWine in his Truth Social post as a "RINO" - or "Republican in Name Only".
US vice-president JD Vance defended his "good friend" Ramaswamy while on the campaign trail in Ohio, his home state, on Wednesday.
In Ohio earlier this month, Vance leaned into other attack ads accusing Acton of alcohol problems.