On March 16, 2015, the world made sense.

One year ago today, Scott Walker and Jeb Bush were neck-and-neck at the top of the Republican field in national polling, as measured by Real Clear Politics. This was to be expected: The popular conservative governor of a Midwestern state versus a scion of the Bush family? Yeah, that’s how Republican politics works. They’d struggle for the nomination, maybe with a senator or two thrown into the mix, and the voters would eventually weigh in.

At this point, that seems almost hysterically naive.

At the beginning of 2015, the three candidates left on the Republican side had the support of only 8 percent of Republican voters — combined. Donald Trump wasn’t even included in polling because, let’s be real, he wasn’t going to run. So it was John Kasich and Ted Cruz, neither of whom were attracting much attention.

Here’s what happened afterward.

The Real Clear Politics average hasn’t yet caught up to the smaller field, so the share held by the three remaining candidates will grow. But it’s nearly a ninefold increase for Kasich, Trump and Cruz since Jan. 1, 2015 — which seems both hopelessly long ago and not that far back.

What that graph really shows, though, is the evaporation of the Republican establishment. Kasich is all they've got now — one candidate with literally no possible way to win enough delegates to be guaranteed the nomination before this summer’s convention. Every other establishment candidate was considered and rejected.

The first candidate to drop out? Scott Walker, whose collapse six months ago was the first of many, as unusual as it seemed at the time.