CLEVELAND – Rep. Thomas Massie (R-Ky.) predicted that any 2016 Republican presidential candidates who do not endorse GOP nominee Donald Trump with the hopes of running for president again in 2020 would lose.

At this point, former Gov. Jeb Bush (R-Fla.), Gov. John Kasich (R-Ohio) and Sen. Ted Cruz (R-Texas) have not endorsed Trump. Bush and Kasich did not attend the convention. Some have speculated that Cruz is positioning himself for 2020 after telling Republicans to vote their “conscience” at the convention.

“Last time I checked, they all took a pledge to back the nominee. And I haven’t said this but I have a friend who asked me: ‘If they can’t keep that simple pledge, why should I trust them in office to keep any promise they made?’ It’s a good point. It’s a question people are asking me,” Massie told PJM at the Republican National Convention.

“It’s a simple enough promise to understand. It’s not complicated like ‘I pledge not to raise taxes’ and then you raise some user fee or something. This is a pledge to back the party’s nominee. Everybody can understand what that promise means and everybody understands they are breaking it,” he added.

Massie explained that he feels “somewhat indebted to the party” to support the nominee because he got involved as a delegate.

“I got involved to try to help Rand Paul. I went to Iowa, so that was the trade I made to be part of the Republican process was the promise that I made myself – I didn’t make it publicly – to back a Republican when we were done with this process,” he said.

According to Politico, Libertarian nominee Gary Johnson has alluded to the possibility of an endorsement from Jeb Bush. Johnson said Bush has reached out to him. Massie was asked for his opinion of Republicans who are considering Johnson.

“If they want to, that’s fine. I don’t really consider Bill Weld [Johnson’s running mate] a libertarian. He’s a moderate Republican from Massachusetts, right? I’m not so sure about Gary Johnson, either. He’s got some positions that aren’t libertarian. It would be hard for me to imagine that a Bush would endorse a candidate who is not pro-life and Gary Johnson is not. I don’t know,” he said. “I don’t want to speculate on that because it’s hard for me to believe.”

Massie said some congressional Republicans refusing to back Trump want to help presumptive Democratic nominee Hillary Clinton and “perpetuate” the status quo in the federal government.

“Definitely Trump is a repudiation of business as usual in Washington, D.C. Hillary is the same thing. There may even be some Republicans who are more comfortable with Hillary because they want to perpetuate the status quo. Trump is definitely a repudiation of the status quo. I understand why they are not here, but I want to say to the folks who think they are going to run in 2020, and are sitting this one out or throwing rocks from the sidelines, you’re going to lose,” Massie said.

“That’s a bad strategy because, number one, I think Trump is going to win and, number two, if he loses and you think you are going to be part of him losing and then just waltz in in 2020 and be, you know, one of the favorite people in the race, I think you need to think again – that’s a bad strategy. I wish they were all here or at least all endorsing – the ones that were in the race,” he added.

When asked what would most likely change under a Trump administration, Massie named immigration policy, trade policy and foreign aid.

“Trump is definitely tacking a different line on immigration. I mean, he’s tacking a different line on trade. I’m pro-free trade, but we have given up a lot of our sovereignty to the World Trade Organization,” he said.

“I haven’t really specifically heard what he says about foreign aid, but I’ve been a little bit disappointed at how many billions of dollars we are sending countries like Afghanistan when we’ve got billions of dollars of unmet need here for infrastructure in the United States so those are the sort of things where’s he’s not tacking the same line as traditional Republicans or traditional Democrats,” he added.