Between 2013 and 2018, South Bend, Ind., Mayor Pete Buttigieg and former Indiana Gov. Mike Pence had a warm working relationship. They had nothing but nice things to say about each other.

But now that Buttigieg is running for the 2020 Democratic nomination, and Pence is to the anti-Trump Resistance the embodiment of pure theocratic evil, the mayor is suddenly a very vocal critic of the vice president.

Humorously enough, when Buttigieg was asked Tuesday evening to respond to critics who have noted his newfound disdain has coincided perfectly with his presidential ambitions, the mayor dodged.

“I’m not a master fisherman, but I know bait when I see it, and I’m not going to take it,” he said to thunderous applause during a town hall event hosted by CNN.

Though the crowd loved the mayor's answer, it does not really do anything to dispute the criticism, which came specifically from U.S. Ambassador to Germany Richard Grenell, who, like Buttigieg, is gay. Unlike Buttigieg, however, Grenell does not claim to dislike Pence, who is very pro-traditional marriage. On the contrary, the ambassador claims to be quite fond of the vice president.

“Mayor Peter has been pushing this hate hoax, along the lines of Jussie Smollett, for a very long time now, several weeks,” Grenell said in a recent interview on Fox News. “And I find it really ironic that Mayor Pete stayed silent about the so-called hate hoax on him and others during 2015, 2016, 2017 when Mike Pence was governor.”

He added: “There was total silence. It’s ironic that right about now when he’s starting his fundraising apparatus to run for president that he comes up with this idea and this attack.”

Indeed, in recent weeks, Buttigieg has not missed an opportunity to take a shot at Pence, despite having what appeared to be a perfectly cordial relationship with the former governor. Such is the mayor’s newfound opposition to Pence that newsrooms are characterizing it as a “feud,” which is a funny way of putting it considering the barbs and criticisms are all coming from one direction.

“Please don't judge my state by our former governor,” Buttigieg told a crowd in Austin, Texas, adding that the former governor has become the “cheerleader of the porn star presidency.” The mayor also accused Pence of advocating for “social extremism.” Buttigieg said elsewhere that Pence is "at best complicit" in the resurgence in white nationalism. Later, during a discussion about his life as a married gay man, Buttigieg brought up the vice president unprompted, saying “that’s the thing that I wish the Mike Pences of the world would understand. That if you have a problem with who I am, your problem is not with me. Your quarrel, sir, is with my creator.”

Pence, meanwhile, has remained mostly quiet, letting loose with only the occasional response, including that the mayor “knows better.”

Grenell, for his part, claims he is friends with Pence. He also claims the vice president “doesn’t have hate” in his heart.

Though I cannot speak for what is in the vice president’s heart, I can say that between 2013 and 2019, the only person to change was Buttigieg. Pence is still the same pro-traditional Christian he was when he occupied the Indiana governor’s mansion. It is Buttigieg who appears to have evolved on the matter of their relationship.

That the mayor's change in tone has coincided with his White House run is a detail that should not be missed.