DONALD Trump has defended a “racist” campaign ad implying that immigration would lead to a spike in violent crime.

Trump said the 30 second film, which was too much even for the usually loyal Fox News to broadcast, was “effective”.

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The advert by Trump’s political team, echoed the controversial “breaking point” campaign used by Nigel Farage days before the Brexit referendum.

The clip showed court footage of Luis Bracamontes, a Mexican immigrant, who in 2014, on a methamphetamine-fuelled

road trip, murdered two Sheriff’s deputies.

The film then cuts to the “caravan”, the large group of people from Central America heading north towards the US-Mexico border that has dominated much of the campaign.

“Dangerous illegal criminals like cop-killer Luis Bracamontes don’t care about our laws,” the advert said, adding: “Stop the caravan. Vote Republican.”

US network NBC and Facebook had both run the advert over the weekend, but backed down on Monday after protests.

CNN had refused to air the film from the start, calling it “racist”.

Fox News distanced themselves from the commercial. President of ad sales, Marianne Gambelli, said in a statement that the network had stopped airing it on Sunday. “It will not appear on either Fox News Channel or Fox Business Network,” she wrote.

Trump told reporters on Monday that he didn’t know about the controversy. “We have a lot of ads, and they certainly are effective, based on the numbers that we’re seeing.

“A lot of things are offensive,” he added.

The actress Debra Messing, whose show Will and Grace airs on NBC, wrote on Twitter that she was “ashamed” that her network “aired this disgusting racist ad”.

Alex Castellanos, a Republican strategist said he couldn’t “remember an ad, ever, that was denied airtime because of its point of view, because it was called offensive or racist”.

Trump posted a longer version of the advert on Twitter, which has been viewed about 6.5 million times.

Americans went to the polls yesterday in the most bitterly contested mid-term elections in a generation. All 435 seats in the House of Representatives are up for grabs, while 35 of the US’s 100 Senate seats are also being contested.

The caravan began on October 12, in the Honduran city of San Pedro Sula when a group of 160 people, eager to escape violence and unemployment, gathered at a bus terminal and set off on a journey that has been a month in the planning.

By the time the caravan into Mexico, its numbers had increased.

Trump has described it as an “invasion of our country” and has sent 5000 troops to the border.