Joe Biden's victory speech on Tuesday had an audience of one

This Biden was more measured, more magnanimous and more conciliatory. There was no gloating or boasting. And everything -- from Biden's tone to the speech he delivered -- was all aimed at convincing Vermont Sen. Bernie Sanders that the time had come to end his primary challenge.

"I want to thank Bernie Sanders and his supporters for their tireless energy and passion," Biden said. "We share a common goal. Together we'll defeat Donald Trump. We'll defeat him together. We'll bring this nation together."

You could be forgiven for thinking after reading those lines that Sanders had already dropped out of the race. Which he hasn't! And in fact, the expectation is that Sanders will continue through next Tuesday -- in hopes that the debate, which will air on CNN on Sunday, will provide him a chance to drastically alter the course of the race.

Which, maybe! But also very unlikely!

But what Biden was very clearly doing in his Tuesday night speech was opening the door for Sanders and his supporters to come in. Not in a hey-man-this-is-over-and-you-need-to-admit-it way, but rather in a gentlemanly way aimed at not further inflaming either the Vermont senator or his supporters.

Which is a very smart move by Biden, although it remains unclear -- at least to me -- if his attempts to bring Sanders into the fold will be successful. Remember that Sanders waited for more than a month after the 2016 primary season concluded to endorse Hillary Clinton. And even after the formal endorsement, Clinton has said she did not feel as though Sanders and his supporters were ever really on board in the general election.

"He hurt me, there's no doubt about it," Clinton told radio host Howard Stern in 2019 of Sanders. "And I hope he doesn't do it again to whoever gets the nomination. Once is enough."

And in recent weeks in this campaign, Sanders has upped the rhetoric against Biden and the broader Democratic political establishment. "The corporate establishment is coming together, the political establishment is coming together, and they will do anything and everything," Sanders said earlier this month. "They are really getting nervous that working people are standing up."

What Biden is trying to do is take away some of the heat from all of this establishment vs. base back-and-forth. And as CNN's Van Jones noted on Tuesday night, Biden is doing so at a critical moment for the Democratic Party. Here's what Van said:

"This is a very dangerous moment for the Democratic Party. You have an insurgency about to be defeated. What do you do with the people you defeat? A lot of young people are going to be crushed. We need to turn to them and say, 'We want to be your champion.'"

Saying it is, of course, one thing. Making it happen is another. But that's exactly what Biden was attempting with that speech -- making clear to Sanders that he would be welcomed with open arms if and when he decides to get behind the former vice president's candidacy.