It was only half a joke when Lyndon Johnson quipped that the White House switchboard could track down anyone, anywhere, at any time. That is, the Texas Democrat clarified, “if he is still living.” And ever since Rutherford B. Hayes had the first telephone installed in 1877, a little platoon of phone operators has made sure that if a president wants to talk, the call goes through.

Sometime on Monday afternoon, they connected 1600 Pennsylvania Ave. with a residence in Wilmington, Del. The former vice president had called the current president to discuss the coronavirus pandemic.

Neither thinks the other is fit to lead the country, but both still said the conversation was productive, and President Trump even seemed charmed by Joe Biden, the man trying to replace him.

According to Trump, it was “a really wonderful, warm conversation.” Views were exchanged and points of disagreement expressed, “and I fully understand that.” The “very friendly conversation” lasted about 15 minutes -- enough to touch the president: “I appreciate his calling.”

Biden said much of the same through a spokeswoman, who described their interaction as “a good call.”

All of this was unusual for two men who publicly doubt the character of the other, and it was made more unusual by the circumstances that brought them together. The hasty détente also didn’t last long. Just hours after they hung up, Biden again criticized how Trump has handled  the health crisis.

“For months, I called on President Trump to step up and take the action necessary to combat COVID-19,” he tweeted along with a link to a Washington Post piece. “But week after week, he downplayed the threat it posed, misled the American people, and failed to act.”

The president did not respond, but his surrogates did. Trump’s campaign communications director fired back that the criticism was beyond the pale. “So much for the nice phone call, huh, Joe?” tweeted Tim Murtaugh.  “It’s all politics with this guy, futilely searching for relevance where there is none.”

Before news broke that Trump and Biden had talked, Trump campaign spokesperson Kayleigh McEnany told RealClearPolitics that the Democrat “continually proves that he is a woefully inadequate leader, unprepared to handle a pandemic like the coronavirus.”

The concern of many in Trump World had been that talking with the presumptive Democratic nominee risked elevating a candidate who has been campaigning in self-isolation. Biden certainly benefited from a call that placed him directly in the news cycle. And while the president insisted that the two had agreed their exchange would remain private, everyone wants to know not if but when the transcript of the conversation will leak. Chris Jacobs, CEO of the conservative Juniper Research Group, wondered what “the over-under on the length of time this pledge will last.” His guess? “One week.”

It isn’t a bad bet given that the pandemic has become the defining political issue of American life in 2020 -- and both campaigns as well. Trump enjoys an unparalleled daily platform with his press briefings while Biden broadcasts his message from a makeshift home studio. All the two seem to talk about are mask production, ventilator stockpiles and the viability of vaccines still in testing.

If anything, it seems somewhat odd that the two didn't talk sooner. Trump has been on the phone with governors and legislators and medical professionals virtually nonstop. He has also made calls to world leaders, celebrities and athletes. He has spoken with Russian President Vladimir Putin about oil prices and chatted with Wolfgang Puck about the difficulties of the restaurant business amid this crisis.

And more often than not, Trump then talks to the press about these conversations. By now, any principal on the pandemic front lines who needs anything from the White House knows how to get ahold of the president. Mike DeWine didn’t schedule a time to chat. He just called the general White House switchboard.

“The president called me back within an hour and a half,” the Republican governor of Ohio told the Wall Street Journal on Saturday. “I said this is just not adequate. He said, ‘I’ll get right on it.’”

If Biden wanted to talk, some White House aides speculated, he could do the same. Instead, negotiations dragged out for more than a week with both camps insisting they’d like to connect. Biden said repeatedly that he would like to talk; Trump said he “would love to speak with him.” But there was a long radio silence. The Biden campaign told RCP that they hadn’t heard anything from the president, and then on Monday the two rivals enjoyed their private conversation.

Details of the call, as of press time, remain unknown, and, for now, Trump still seemed charmed by the little correspondence. He has not yet tweeted or spoken critically of Biden.

Correction: Due to an editing error, an earlier version of this story erroneously attributed a comment from Kayleigh McEnany to Tim Murtaugh.