The day Donald Trump steps onto stage to accept the Republican nomination for the presidency will mark 50 weeks to the day since the first Republican debate, a neat little bookend to a long campaign season. That first debate was the first time we saw all of the top Republican contenders -- including Trump -- in one place. It was the night that Megyn Kelly and Trump fought over his disparagement of women. And, coincidentally, that debate was held in the very same arena where the balloons will fall around Trump and his family.

The day before Trump gives his acceptance speech, the last bit of tension from the primary contest erupted toward the end of a speech given by Sen. Ted Cruz, the man who came in second in the delegate count. Cruz declined to endorse Trump specifically, instead saying that he hoped conservative values would prevail in the election, which isn't quite the same thing. Delegates shouted at Cruz to endorse, to no avail. Anarchy.

Fifty weeks (minus one day) before, though, Cruz had pledged to do exactly that. Fox News launched that first debate by asking one question: Did any of the ten candidates on the stage not pledge to back the Republican nominee, should it not be them? One hand went up.

None of the other nine people on the stage raised their hands. So did they keep their pledges?

Chris Christie was at the far left end of the stage, ranking ninth in polls leading up to the first debate. Christie was the first of the bunch to endorse Trump, giving the eventual winner his endorsement early enough that it caught observers by surprise. He spoke on the second night of the convention.

Marco Rubio was next. He ... sort of kept his pledge.

Not an endorsement, but a vote? It's not worth parsing the word "pledge" too much, but we'll count it. Rubio refused to attend the convention, but taped a testimonial that aired on night three.

Ben Carson was in fifth place in the polling for that first debate, before rising and falling quickly before the end of the year. He backed Trump after Christie but hit the trail eagerly afterward. He spoke on day two of the convention.

Scott Walker was polling in third in early August, before collapsing. He was similarly vague about his endorsement earlier this month, but put a fine point on it this week. He spoke before Cruz.

Jeb Bush was standing next to Trump at center stage for that first debate, gradually sliding to the edges as the debates went on, until he dropped out of the race. He has refused to endorse Trump and has continued to attack the nominee, even after being beaten. Trump, frustrated, has suggested that there be repercussions.

"They broke their word, in my opinion. They should never be allowed to run for public office again because what they did is disgraceful," he said last month.

Mike Huckabee was in fourth place for that first debate, just right of center stage. He endorsed Trump in May.

Cruz was next, followed by Rand Paul. He endorsed Trump at about the same point as Huckabee, despite having referred to Trump as "a delusional narcissist and an orange-faced windbag" a few months earlier. Why did Paul endorse? "I took a pledge when I ran for president to not run as an independent candidate and to support the Republican candidate," he said. "I stand by that pledge."

At the far right of the stage, in tenth place in the polling, was John Kasich, governor of Ohio. Kasich was happy to be at that debate, having just jumped into the race -- and because it was in his home state. But that pledge wasn't even motivation enough to get him to take the two-hour drive up I-71 from Columbus. Kasich has refused to endorse, and refused to attend the convention in his state.

Of those first ten candidates, in other words, nine pledged to support the eventual nominee, and one didn't. The one who didn't became the nominee, and only five of the other nine extended full-throated endorsements as a result. Three of the four who didn't, including Rubio, were the runners-up in that race. The fourth, Jeb Bush, simply seems to have taken it personally.

Fifty weeks after that first debate, Trump has shut the door on the primary season. But he still hasn't won everyone over yet.