They didn't appear on the same stage, but Donald Trump and Joe Biden were in the same state yesterday, appearing on behalf of two senate candidates locked in a tight race. With Trump's renomination virtually assured and Biden leading the potential Democratic presidential field, the competing rallies were a preview of what might transpire in 2020.

Trump was in Nevada to talk up a former foe - incumbent Senator Dean Heller. At one time, Heller heavily criticized Trump. But the two have kissed and made up and Trump has spoken warmly of Heller in recent months. Biden was in Nevada to tout the Democratic senate candidate, Rep. Jacky Rosen. Heller and Rosen are neck and neck in the polls and with the election a little more than 2 weeks away, the visit by the two party leaders shows the importance Democrats and Republicans see the race.

Politico:

“It’s not enough to just show who they are,” Biden said of Trump and Republicans. “We’ve got to tell them who we are. What do we stand for. What does the Democratic Party stand for today?”

Biden also touted his close relationship with former President Barack Obama, who won Nevada twice and will headline a rally for Senate hopeful Jacky Rosen here on Monday.

“He’s a good friend, man,” Biden said. “I want to make it clear: all those memes, they’re basically true. He made the first friendship bracelet, not me.”

With anecdotes like that, Biden was easy pickings for Trump:

Trump, rallying the GOP base in the northern city of Elko, labeled the Democrat “Sleepy Joe Biden” and “One Percent Joe,” mocking both the size of the crowd at Biden’s event and the former vice president’s past failed presidential campaigns. Biden responded in kind, telling the crowd of several hundred outside the local Culinary Union here that Trump was “shredding” basic decency and making a deliberate effort to divide the country.

[...]

“I think he ran three times, and he never had more than 1 percent, so we call him, ‘One-Percent Joe,” Trump said.

“And then remember what happened?” he continued. “Obama came along and took him off the trash heap and made him vice president. But he never had more than 1 percent.”

Biden will no doubt be a formidable candidate, both in the primaries and general election. But younger Democrats are uneasy with him and the entire party is well aware that he will be almost 77 years old on election day in 2020. But Biden and the other Septugenarians running for the Democratic presidential nomination will raise the lion's share of the money, sucking the oxygen out of the race that younger candidates would need to win.

Trump will be virtually unchallenged, although a NeverTrump candidate will be expected. If the two men do indeed meet in 2020, it will almost certainly be the most vicious national election in history given the street fighting capabilities of both candidates.