... and what he can lose by delaying the endorsement.
In my previous post on limits, I posited that there is a point at which Sanders' withholding endorsement of Clinton starts to lose him influence. That is, Sanders' "taking it to the limit" is likely to cost him. I'm now thinking that the inflection point - the point at which Sanders' gains tip and become losses - is in Orlando on July 8th and 9th when the full Democratic platform committee meets. Waiting till the convention will not gain Sanders much more than he has already achieved and doing battle at the convention might be divisive to the party while not netting Sanders very much. After all, crafting the platform is negotiation, and Clinton did win the most votes. "Everything" for Sanders is not on the table.
Joan Walsh of The Nation also assesses the advantages and disadvantages of Sanders delaying an endorsement.
If you told me before I left on vacation two weeks ago that when I returned Senator Bernie Sanders would have secured huge Democratic platform concessions—a commitment to a $15-an-hour minimum wage, a death-penalty ban, a financial-transaction tax, a modernized version of “Glass-Steagall” banking regulations, a surtax on multimillionaires, Social Security expansion, among other priorities—I’d have expected to see Sanders out campaigning with Clinton this week, having enthusiastically endorsed her.
Instead, Clinton campaigned with progressive icon Elizabeth Warren on Monday, while Sanders continues to say he’ll withhold his support until the Democratic National Committee grants him even more platform wins. My Sanders supporter friends have told me, over the last two months, that their candidate has to hold out to secure the best platform when the party gets to Philadelphia. That may have been true until the last week. But I think Sanders risks weakening his negotiating position by delaying to endorse Clinton, while insisting she and the party accept his every campaign plank, including a single-payer health-care system, a fracking ban, and an aggressive promise by Democrats not to vote for the Trans-Pacific Partnership. (Clinton, like Sanders, opposes the TPP, as do the majority of the DNC platform committee. But the committee voted not to demand a no vote on the trade deal, in order to avoid embarrassing Obama, who is still pushing Congress to approve the TPP.)
Of course, Sanders and his supporters can continue to fight for their planks, with the full platform committee in Orlando, and even on the convention floor in Philadelphia. That’s happened before; it hasn’t destroyed the party. What will be destructive, however, is if Sanders continues to tie his endorsement to Clinton’s accepting his remaining platform demands. She can’t, and she won’t. Sanders may even be setting himself up for less influence in Philadelphia, rather than more, with this ongoing crusade. There are certainly progressive Clinton delegates who might want to vote to strengthen the minimum-wage language, or oppose the TPP, to put the party on record behind more progressive goals. But if Sanders is holding Clinton hostage to winning on those issues, not one Clinton delegate will consider anything he’s asking.
... [Keith Ellison] thinks there’s a downside to Sanders and his surrogates’ enthusiastically backing Clinton too soon: that the senator’s younger supporters will feel abandoned, and won’t come along with the nominee in November.
But there are also risks to waiting too long. Senator Elizabeth Warren has already emerged as a Sanders stand-in, and she’s doing a great job. Meanwhile, if Clinton is forced to court “Never Trump” Republicans because Sanders delivers a late or halfhearted endorsement, he and his backers will lose some influence politically. There are many Republicans available to Clinton, particularly women, if she decides that’s her best audience. As one Clinton supporter close to the platform negotiations told me: “It’s really up to him: He can determine if she does this with a progressive mandate, one that she has to be loyal to. But if his voters snub her, and she has to go to anti-Trump Republicans to get to 51 percent, they’ll have much less leverage.”