There was an extraordinary moment during yesterday's Presidential debate.
As he discussed the war in Syria, Donald Trump openly contradicted his own vice-presidential nominee, Mike Pence. On live television. With tens of millions of people watching. That's pretty much unheard of in an election campaign, when the two halves of the ticket are supposed to be perfectly in sync.
Trump ran into trouble when he criticised Hillary Clinton's stance towards Russia and Bashar al-Assad's Syrian government.
"(Clinton) talks tough, she talks very tough against Vladimir Putin and against Assad. She talks in favour of the rebels. She does not even know who the rebels are," Trump said.
"She wants to fight, she wants to fight for rebels. There is only one problem. We don't even know who the rebels are.
"I do not like Assad at all but they are killing ISIS, Russia is killing ISIS."
Moderator Martha Raddatz jumped in, trying to clarify Trump's position.
"I want to remind you what your running mate said. He said provocations by Russia need to be met by American strength, and that if Russia continues to be involved in air strikes along with the Syrian government forces, the United States of America should be prepared to use military force to strike the military targets of the Assad regime," Raddatz pointed out.
"He and I have not spoken, and I disagree," Trump replied. "I disagree. I think we need to knock out ISIS. Right now Syria is fighting ISIS. We have people who want to fight both at the same time. Syria is no longer Syria. Syria is Russia and it is Iran, who she (Clinton) made strong.
"I believe we have to get ISIS. We have to worry about ISIS before we can get to much more."
Trump's assessment of Assad and Putin's intentions in Syria was a little iffy, but regardless, he threw Pence under the bus without a moment of hesitation.
Raddatz was right. During last week's vice-presidential debate, Pence said the United States should consider taking military action against the Assad regime in Syria. He also had some very harsh words for Russia.
"Hillary Clinton's top priority when she became Secretary of State was the Russian reset. After the Russian reset, the Russians invaded Ukraine and took over Crimea. And the small and bullying leader of Russia is now dictating terms to the United States," Pence said.
"I just have to tell you that the provocations by Russia need to be met with American strength. And if Russia chooses to be involved and continue, I should say, to be involved in this barbaric attack on civilians in Aleppo, the United States of America should be prepared to use military force to strike military targets of the Assad regime to prevent them from this humanitarian crisis that is taking place in Aleppo."
This is an utterly bizarre situation. Trump and Pence are running to be president and vice president in the same administration, but the two men are presenting completely different views on foreign policy to voters.
By Trump's reckoning, Vladimir Putin and Bashar al-Assad are both focused on defeating the Islamic State in Syria. According to Pence, the Assad regime is murdering civilians and Russia is enabling it.
Trump thinks he can orchestrate a friendship between Russia and the United States, while at the same time, Pence is actively arguing for military strikes against Russia's close ally.
Trump has been complimentary of Putin on multiple occasions, calling him a "strong leader", among other things. Pence just described Putin as "small and bullying".
You could be forgiven for thinking these guys were running against each other.
Trump's blunt debate slapdown could not have come at a worse time either, because the cracks between him and Pence had already widened significantly over the weekend. Pence, a staunch social conservative, didn't even try to defend Trump after the release of an explosive video from 2005, in which Trump bragged he could "do anything" to women because of his celebrity status.
"As a husband and father, I was offended by the words and actions described by Donald Trump in the 11-year-old video released yesterday. I do not condone his remarks and cannot defend them," Pence said in a statement.
According to a source close to the Trump campaign, who spoke to Washington Post reporter Philip Rucker, Pence was "absolutely apoplectic", "melting down" and "inconsolable" after the video was leaked. There was speculation that he was thinking about quitting the race.
That talk appears to have blown over for now, even though Pence has rather suspiciously cancelled his appearance at a fundraiser he was supposed to attend tomorrow.
According to the Indianapolis Star, the main newspaper in Pence's home state, the vice-presidential nominee is publicly sticking with Trump, but privately keeping his options open.
He was said to be keenly observing today's debate - and thankfully for Trump, it seems he was impressed.
But whatever happens in private in the coming days, the two men can't afford to stay at odds with each other for long.
"That there is a significant rift between Pence and Trump is in little doubt," the conservative news site RedState wrote today.
"This is no honeymoon. It is at best a buddy cop movie where we're still in the part where they haven't become buddies yet."
We can't put it any better than that.