"Special guest" Sen. Bernie Sanders endorsed his rival for the Democratic presidential nomination, former Vice President Joe Biden, during a livestreamed video conference Monday. But will the Bernie supporters care?

Any hopes that the heartfelt endorsement would end the long-boiling tensions between the party's liberal and moderate wings quickly went up in steam as a couple of prominent Sanders supporters tweeted out their dissatisfaction.

"With the utmost respect for Bernie Sanders, who is an incredible human being & a genuine inspiration, I don't endorse Joe Biden," tweeted Briahna Joy Gray, Sanders' former national press secretary. "I supported Bernie Sanders because he backed ideas like #MedicareForAll, cancelling ALL student debt, & a wealth tax. Biden supports none of those."

No, but he does support more moderate alternatives to all three of those goals. For example, Biden would offer a choice between private health insurance and a "public option." Sanders would exclude the choice of private insurance, for which he was opposed by labor unions that are trying to protect the plans they have won through many years of negotiations with management.

Gray, by contrast, called it "almost insulting" for Biden to suggest lowering the Medicare eligibility age to 60, in lieu of adopting universal health coverage.

Progressive journalist-activist Shaun King, a Sanders surrogate, also chimed in with this criticism: "In his conversation with @BernieSanders, @JoeBiden is clearly reading from a TelePrompTer. It's supposed to be a CONVERSATION. I've never seen this happen in my entire life."

Considering how Biden is running against President Donald Trump, for whom the teleprompter has not always been a friend, you might think the left would be relieved. Not King. He posted an opinion piece outlining a list of requirements for his endorsement and alleging that Biden "blatantly lied" about his past participation in the civil rights movement.

These are the sort of attacks from one's own side that are hardly unique to Democrats. Remember RINOs? Short for "Republicans in name only," that was a right-wing put-down of the party's moderates who supposedly were not conservative enough. Today, there's little doubt that the party has moved to the right with Trump's rise, which is what progressive-wing Democrats want their party to do in the other direction.

All of which brings up an adage I first heard from Democratic consultants in the early 1990s: Republicans fall in line, Democrats fall in love — or want to. We've seen that maxim in action most recently in the 2016 presidential race. Remember how fiercely Trump's rival candidates opposed the interloper who trolled his opponents with insulting nicknames, scoffed at "political correctness" and refused to swear loyalty to the party's nominee unless it was him? Remember how rapidly their opposition evaporated after he began to win primaries?

Remarkably, the party bigwigs fell in line behind Trump, albeit begrudgingly. Sen. Ted Cruz, the last major holdout, was literally booed off the stage at the party's Cleveland convention for refusing to give a full-throated endorsement of Trump, who had insulted members of Cruz's family.

Democrats have their family feuds, too, but a bigger factor these days may well be their quest for another Barack Obama, who endorsed Biden on Tuesday in a video message. Remember how he captured the party's hearts in their 2004 convention when, by his own account, he was better known as "the skinny kid with the funny name?"

He was a tough act to follow, as Hillary Clinton found in 2016 after Trump's widely unexpected victory.

Now it's Joe Biden's turn to try his third attempt to win the White House and hope it's a charm. After winnowing down the field from more than two dozen initial candidates, the Democratic Party has ended up with one of its most familiar — and longest-tenured — figures, who has to contend with speculation that he's too old for the job.

Well, as Trump likes to say, constantly, we'll see what happens. After all the flash and excitement of the racially, gender and ideologically diverse candidates who entered the race, Biden's victory shows a general consensus that he represents, at least, a return to a traditional presidency after years of the colorful, changeable reality-TV Trump.

In that sense, Trump has become as unifying of a figure for Democrats as Clinton was for Republicans.

Clarence Page's columns are distributed by the Tribune Content Agency.