CLEVELAND — As Mike Pence accepted the Republican Party's nomination for vice president, I witnessed a supporter of Donald Trump and a Ted Cruz backer in a nearly chest-to-chest shouting match in the back of the convention floor, fighting over Cruz's non-endorsement.

"We're working hard for conservative principles, but the only way to beat Barack Obama and Hillary Clinton is to unite — "

Before the Trump supporter from Arkansas could finish, a Cruz supporter I later identified as Colorado delegate and lawmaker Justin Everett interjected: "By selling out our principles?"

After the uproar on the floor generated by Cruz's speech, which had him leaving the stage to a booing crowd of Trump supporters, a debate immediately broke out over whether he owed it to the party to endorse the nominee.

Putting aside that question, it isn't fair to say that Cruz caused the disunity that we witnessed on the convention floor on Wednesday night. All he did was expose the lie at the heart of this convention — the lie that this is a party that has any real sense of unity.

This convention is a charade. Party leaders and those from the Trump campaign keep insisting that Republicans are coming together behind the nominee in a way that could make Baghdad Bob blush.

The reality is quite different.

Last week, the party had a bitter battle over rules with many delegates pushing to unbind them so they could vote against the party's nominee. On Monday, the convention convened with party leaders shutting down an anti-Trump drive for a roll call vote on the rules.

The chairman of the convention, House Speaker Paul Ryan, hemmed and hawed for months over whether to endorse Trump, and has spent much of his time during convention week talking about his own policy agenda.

Though we're used to defeated rivals appearing on stage to enthusiastically throw their support with the nominee, Gov. Scott Walker endorsed Trump without saying anything positive about him beyond his name not being Hillary Clinton. Sen. Marco Rubio couldn't bring himself to attend, and instead thread the needle with a short video message.

Dozens of prominent Republican elected officials chose to skip the convention altogether.

There is no true functional coalition of Republicans. The party is not uniting around Trump. All Cruz did was expose what is blatantly obvious to every intellectually honest person.