Marco Rubio stood on stage at a recent Republican primary debate and reluctantly said that he would support the GOP nominee no matter what.

He was joined in that confession by candidates John Kasich and Ted Cruz.

While it’s likely that Kasich and Cruz remain men of their words, the likelihood that Marco Rubio follows suit is pretty low. Here’s why.

Marco Rubio Resents Trump For How He Influenced Rubio’s Campaign For The Negative

When the GOP primary candidates dwindled to five, Rubio saw it as his opportunity to surge ahead of Trump, leading to a combative debate that many feel he got the better of, though it did him little good in the polls.

Rubio attempted to take on Donald Trump on Trump’s terms — by going into the gutter with insults and surface-level criticisms. What was once a principled campaign became Donald Trump Lite, and why go with Lite when you can get the real thing?

Marco has since expressed regret for “going there” with Trump. What once was a promising political career morphed into a campaign about “small hands, small penises” virtually overnight. Not only did it torpedo Rubio’s shot at the nomination, but it may have placed his entire career in jeopardy.

Marco Rubio Has Said Too Many Negative Things About Trump For An Endorsement To Make Any Sense

Rubio has done everything in his power to convince Republican primary voters to back his campaign, but more and more, it looks like his only chance at the nomination is through a backdoor brokered convention.

He certainly doesn’t have the voter support with less than 200 delegates this late in the cycle.

Cruz is the only somewhat-establishment Republican with a shot of unseating Trump, and he’s the only one likely to keep many of Trump’s supporters on the GOP side.

Rubio knows that his days are numbered in this race, yet he continues to throw punches. Hardly the actions of a man intent on eventually accepting Trump’s inevitability.

His most recent comments targeted the cancellation of Trump’s Chicago rally after violent protesters associated with a pro-Bernie Sanders group forced the event to be postponed indefinitely.

Rather than seizing on the obvious breach of Trump’s and his supporters’ right to free speech, Marco Rubio blamed Trump, wedging a divide between the two that will prove impossible to bridge once the nomination is secure and this heads toward a general election.

A Trump endorsement would only make Marco Rubio appear weaker and more defeated than he already is, and it would pigeonhole him as being a typical politician that only says what he thinks will help him instead of what he really feels.

Donald Trump Is Not The Republican Party Rubio Signed Up For

Say what you want about Trump’s truthfulness, but he has been right about one thing in particular. His supporters are as much Independents and disenfranchised Democrats as they are traditional Republicans.

Marco Rubio is a purer form of Republican, and resents the party’s expansion under Trump’s ideology. He doesn’t view Trump as the Republican frontrunner. He views him as a parasite sucking the party dry while building something altogether different.

When Trump wins, he will be the leader of a new movement, not the Republican party — at least in Marco’s mind.

While backing down on his pledge to support the Republican nominee if it is Trump wouldn’t be good for Rubio in the short term, it could save his long-term political career, especially if Trump loses the general election or wins and does a terrible job.

For all these reasons, you should not expect a Donald Trump endorsement coming from Marco Rubio any time soon. But what do you think, readers? Will Rubio be a man of his word and endorse Trump, or will he back out?

[Image via Marco Rubio/Facebook]