Republican John Hammond III had made no secret of his distaste for Donald Trump and his desire to thwart his march to the party’s presidential nomination, telling the Indianapolis Star newspaper in March that the mogul was “unfit” to lead the United States. But the Republican National Committee member, a partner at law firm Ice Miller, said no anti-Trump group ever reached out to him, nor did he see any evidence that such groups were in the state until just a few days before voting in Indiana’s primary election. By the time some direct mail and TV ads popped up, it was “too late” to make a difference, he said. “There was never really any early ‘Stop Trump’ effort in Indiana,” he told recently. Trump became the Republican party’s presumptive nominee on Tuesday with his resounding win in Indiana’s primary, which led his main rival US Senator Ted Cruz of Texas to drop out and heaped pressure on distant third-place contender John Kasich, the Ohio governor, to do the same. In the process, Trump dealt a seemingly fatal blow to the high-profile effort known as “Stop Trump” or “Never Trump” launched by conservative Republicans. The movement — led by the conservative anti-tax non-profit Club for Growth and the Our Principles PAC — for months failed to significantly slow Trump’s momentum and now appears to be on death watch, political operatives and at least three officials involved in the movement say. It emerged over the US winter as initial skepticism over Trump’s chances turned to anxiety among conservatives, who view many of the Manhattan real estate mogul’s policy pledges as a liberal threat to their low-tax, low-spending principles. But from the start it was hobbled by poor coordination, the lack of a single, influential public leader, and the absence of an agreed-upon alternative to Trump, according to leaders in the movement as well as Republican operatives familiar with it. “You have to have a plan of action to deal with him,” said Republican strategist Doug Heye, a Trump opponent who has ties to people in the movement. “And it appears no one really did.” Publicly, leaders in the Stop Trump movement dispute the notion that they were ineffective, saying their efforts in Wisconsin helped head off a Trump win in April. They also say the groups communicate effectively with one another and that they will continue fighting despite the Indiana results. “We will continue to educate voters about Trump until he, or another candidate, wins the support of a majority of delegates to the Convention,” Katie Packer, chair of the Our Principles PAC said in a statement. But, in private, three top officials associated with the movement conceded that Indiana was a “do or die” moment. The movement suffered a major setback when Republican mega donors declined to play the role of “Trump Slayers.” Both casino magnate Sheldon Adelson and the billionaire industrialist Koch brothers, decided not to repeat their experience in 2012, when they lavished hundreds of millions of dollars on Republican candidates only to see no returns. Deprived of such major financial backers, Club for Growth and Our Principles PAC together spent only $27 million on anti-Trump messaging, according to Federal Election Commission reports. Democratic front-runner Hillary Clinton’s campaign and Super PAC have spent at least $78 million so far, according to FEC reports. The groups and their associates focused their messaging over the winter and spring on television and social media ads and Twitter blasts highlighting Trump’s comments about women being “bimbos,” “dogs” and “fat pigs,” as well as his statements supporting universal health care and higher taxes. Throughout their campaign, the two groups did not coordinate directly with one another or even converse on a regular basis, according to one Club for Growth official. It wasn’t until last week that Our Principles PAC and the Stop Trump effort in California, led by political consultant Rob Stutzman, even joined forces. Officials at Club for Growth said they weren’t aware of that California effort. Some veteran Republican operatives said Our Principles PAC had been a waste of time and money. “They’ve had no leadership. They’ve spent tens of millions of dollars by now and gotten zero message, zero movement,” said one Republican familiar with the workings of the movement. “The whole thing has been a disaster from the beginning.” Many donors, like Trump’s rival candidates, underestimated the tycoon, believing he would burn out after his early successes, Republican consultants say. Those who did come forward publicly to support the Stop Trump movement, such as Chicago Cubs owners and Our Principles PAC funders Joe and Marlene Ricketts, were swiftly treated to Trump’s social media wrath. “They better be careful,” Trump said of the Ricketts in a Tweet in February. ”They have a lot to hide!” By March, other wealthy families who had donated to the cause were asking reporters not to identify them in stories anymore because they didn’t want their spouses and children to face “abuse” from the Trump campaign. “I don’t think you can underestimate how effective Donald’s bullying has been, even among wealthy donors,” said one top official at Club for Growth. Trump campaign manager Corey Lewandowski dismissed the notion that donors had been fearful, saying the identity of campaign contributors has long been public information.