Why the Bernie Sanders endorsement of Joe Biden means less than you think

"We need you in the White House," Sanders told the former vice president in a livestreamed conversation. "I will do all that I can to see that that happens, Joe."

Pro-Biden Democrats were quick to note that Sanders' endorsement of Biden in 2020 came far faster (and earlier) than his endorsement of Hillary Clinton in 2016. (Sanders endorsed Clinton in July 2016, more than a month after the end of the primaries.)

True! And far better to have Sanders on the record endorsing Biden than, well, not.

But don't assume that simply because Sanders has formally endorsed Biden that the legion of supporters who have backed the Vermont democratic socialist in both of his presidential races will suddenly flock -- or even meander -- toward Biden.

"With the utmost respect for Bernie Sanders, who is an incredible human being & a genuine inspiration, I don't endorse Joe Biden," tweeted Sanders 2020 national press secretary Briahna Joy Gray shortly after the endorsement went public. "I supported Bernie Sanders because he backed ideas like #MedicareForAll, cancelling ALL student debt, & a wealth tax. Biden supports none of those."

Gray is, obviously, just one person. But so much of Sanders' appeal is tied into his support for "Medicare for All" (a policy Biden does not support) that it won't be as simple as Sanders saying "I endorse Joe" to convince his followers that the former VP is the right choice.

Now, that's not to say that lots of Sanders' supporters will back President Donald Trump in the fall.

In 2016, one study showed that roughly 12% of Sanders' backers voted for Trump in the general election. It's hard to see that number being anywhere close to as high in 2020 -- given how much anger and unhappiness Trump's first three-plus years in office has caused liberals.

But that's not even the real danger here for Biden's general election chances. The real issue would be if dispirited Sanders backers simply decided to stay home on Election Day. That erosion in the Democratic base vote could badly hamstring Biden's campaign.

The Point: Saying the words "I endorse" won't magically make every Sanders backer a Biden person. Not by a long shot.