Donald Trump got an interesting endorsement Monday.

Brian France is the chief executive and chairman of NASCAR, the car-racing organization. France endorsed Trump (which is a funny sentence in itself), although NASCAR as an organization did not. Regardless. France endorsed Trump.

Close observers of this weird election cycle, though, may remember NASCAR having come up before. In early July 2015, NASCAR moved a series of banquets away from Trump's Miami resort facility in the wake of his campaign-launch comments about Mexican immigrants.

Remember that? It seems so long ago now. Trump comes down the escalator at Trump Tower, all of us agog that this was actually happening, and quickly launches into a tirade about how Mexico is sending criminals over the border. That lit a slow-burning fuse that, a few weeks later, spurred Univision to cut ties with Trump over the Miss Universe pageant -- drawing huge media attention to Trump's comments which then prompted other companies to weigh in.

The chief executive of Camping World, sponsor of one of the NASCAR banquets, wrote a letter to France that read, in part, "Our company will not stand to support any person or organization that associates with such beliefs and we feel strongly about distancing ourselves from any negative and discriminatory comments made against any gender, ethnicity, age group or so forth. I would hope that the entire NASCAR organization would agree with my sentiments." Shortly after that letter was released to the media, the events were moved. "We looked at everything we saw coming down," a NASCAR spokesman explained, "and what we heard from our sponsors and our partners and what we feel we should be doing, and that's what led us to the decision today."

Former NASCAR driver Bill Elliott gestures toward Republican presidential candidate Donald Trump during a campaign rally at Valdosta State University. (Philip Sears/Reuters)

Those comments about Mexicans lit another fuse, too. After the Univision fight brought attention to Trump and his stance on immigration, support for him exploded among Republican voters. His campaign launch was in mid-June and the boycotts happened at the end of that month. By mid-July, right about the time that Trump was dismissing John McCain's war record, Trump seized the lead in the Republican race -- and has held it ever since.

In concert with that, opinions of Trump among Republican voters have turned around. In Monmouth University's poll in June, 20 percent of Republicans viewed Trump favorably and more than half of Republicans looked at him unfavorably. By the July poll, taken right before he gained the lead, the electorate was about split. And then he became more popular than unpopular.

In the month since voting began, something else has happened: The heart of the establishment has started reaching out to Trump to make friends. He got the endorsement of New Jersey Gov. Chris Christie and got his first endorsements from Capitol Hill. The guy who nine months ago was a persona non grata is now viewed positively by most Republicans and a chunk of the party's insiders. If you want to endorse Trump, in other words, you have cover. People can't say that he is a pariah without disparaging the 49 percent of Republicans who want him to be president. For a corporation -- those masters of gauging where the wind is blowing -- endorsing Trump no longer makes you a racist.

And that, in a nutshell, is the Trump campaign. Corporations, pundits and voters who criticized him as a joke who wouldn't go anywhere near him are now welcome to treat him like any other presidential front-runner. The circle of political life is complete.