Video: Ted Cruz refuses to endorse Donald Trump in his RNC speech

The Republican National Convention crowd turned on Sen. Ted Cruz when he said three little words: "vote your conscience."

Up until that point, Republicans at the Quicken Loans Arena had largely been with Cruz during his paeon to conservative values. But the "vote your conscience" line, an indication that he wasn’t going to endorse Donald Trump and a nod to the NeverTrump movement’s quixotic quest to allow delegates to nominate whomever they wanted, riled up the Trump fans in the crowd.

That’s when the shouts began — "We want Trump!" "Keep your pledge!" "Go home!" — and, after Cruz switched from his plea for voters to show up to the polls and vote in all the other races on the ticket, the boos drowned out the final moments of his speech. Cruz acknowledged them with a jokey nod to the New York delegation, but other states, including California, were doing their fair share.

"Toward the end, where the other speakers would say, ‘This is why we need Donald Trump,’ he just said, ‘Vote for your conscience,’" Nancy Weres, a California delegate sitting in a particularly vocal section of the stands, told me. "That doesn’t mean anything."

It was an extraordinary moment not seen in decades on a major party’s convention floor, ever since presidential primaries turned the nominating process at political conventions from a battle into a fait accompli.