WASHINGTON • More than half of the record spending on negative advertising during the 2016 presidential primary has been directed at a single candidate, Mr Donald Trump, in a barrage that threatens to undermine his candidacy even as he continues to march towards the Republican nomination.
Of the more than US$132 million (S$178 million) spent on negative ads by candidates and the groups supporting them, nearly US$70 million has gone to commercials assailing Mr Trump, according to a New York Times analysis of data provided by Kantar Media/CMAG.
The sharp focus on a single candidate is especially surprising given the race's exceptionally large number of primary contenders.
In addition to Mr Trump's opponents, three Republican super- PACs or political action committees have made it their main focus to take him down.
The Club for Growth, Our Principles PAC and the American Future Fund, all unaligned with any particular candidate, have spent more than US$23.5 million on negative ads against the billionaire.
The system is rigged, it's crooked.
DONALD TRUMP, on Fox News on Monday. He has alleged that the Colorado convention results show voters were being denied a voice in the process.
On Monday, Democratic candidate Hillary Clinton crossed primary lines to add to the onslaught, releasing a commercial that highlights comments Mr Trump has made about immigration and abortion, and argues that he is trying to get Americans to turn against one another.
The New York tycoon, meanwhile, lashed out at what he called the Republican Party's "rigged" delegate selection rules after rival Ted Cruz swept all of Colorado's 34 delegates over the weekend.
Mr Trump, who has been outmanoeuvred by Mr Cruz in a series of recent state meetings to select national convention delegates, said the process was set up to protect party insiders and shut out insurgent candidates.
"The system is rigged, it's crooked," Mr Trump said on Fox News on Monday. He alleged that the Colorado convention results showed voters were being denied a voice in the process.
Mr Trump has 743 bound delegates to 545 for Mr Cruz, according to an Associated Press count, in the battle for the 1,237 delegates needed to win the nomination on the first ballot and avoid a messy floor fight at the Republican National Convention from July 18-21.
But both are at risk of not acquiring enough delegates for a first-ballot victory, leaving many free to switch their votes on later ballots.
That has set off a fierce scramble by Republican candidates to get their supporters chosen as convention delegates, and brought new scrutiny to the selection rules, which vary by state.
NEW YORK TIMES, REUTERS