After his crushing defeat by Donald Trump in Indiana, Ted Cruz suspended his nomination campaign, essentially clearing the way for Trump since he was his only rival who had some shot in winning. A little later, John Kasich followed, with a statement in which he did not mention Trump in any way, nor whether he would support him as the party nominee.

Kasich position reflects the feelings of many republicans. The only two living former Republican presidents of the United States, George HW Bush and George W Bush already announced they will not endorse Donald Trump.

Freddy Ford, a spokesman for George W Bush, told the Guardian: “President George W Bush does not plan to participate in or comment on the presidential campaign”.

Jim McGrath, a spokesman for George HW Bush, told the Guardian: “At age 91, President Bush is retired from politics. He naturally did a few things to help Jeb, but those were the exceptions that proved the rule”.

They do not stand alone. Other senators, such as Dean Heller of Nevada and Ben Sasse of Nebraska have already made clear they will not even vote for Trump in November, when the elections take place. Senators Kelly Ayotte of New Hampshire and Rob Portman of Ohio have said they will vote for the party’s nominee but will not endorse Donald Trump.

These statements only begin to describe the challenges Trump will face in uniting the Republican party, which his candidacy deeply devided. As the New York Times put it, many Republican elected officials, donors and strategists found themselves “in a state of political paralysis”.

Even Republican representatives who pledged support for Mr. Trump, like Peter T. King of New York sound critical: “As far as any involvement or campaigning, it’s really going to depend on him filling in the gaps and consolidating his policies. Right now, there’s no real coherence”.

Meanwhile, Hillary Clinton already stepped up with her campaign against Trump, releasing a video on Thursday that showed former Republican candidates attacking him and a compilation of prominent conservatives who are all refusing to back Trump in November.

And of course a collection of some of Trump’s positions which could be reason enough anyway: