A good friend of many years wrote to me last week arguing that Hillary Clinton has the lion’s share of the responsibility to unify the Democratic Party. Hillary, he said, must substantively reach out to Bernie in both words and practical deeds soon if she has any hope of getting elected.

I agreed with him, but I also see the process of how that has to happen a little bit differently. I would argue that it is imperative that both sides – Sanders as well as Clinton – show a spirit of compromise and accent their common battle against Trump, not hostility toward each other. Hillary should soon make meaningful concessions to Bernie, but Bernie and his supporters should realize that they can’t expect all of their demands to be met either. They too have to bend.

Let’s not forget that Bernie, notwithstanding all the claims and protests of his supporters, was the loser in this contest. Hillary was the winner – in both votes cast and delegates won.

The best scenario, as I see it, would be for Bernie to give up his run for the nomination after the last vote is cast on June 14 in the D.C. primary. At that time, he can (and should) continue to press his case on other issues – the party platform, convention rules, delegate seating, his role, and so on. But to continue his campaign for the nomination all the way up to the convention in late July, however, strikes me as a dangerous roll of the dice.

Trump could easily be the big winner, while Hillary and the American people could be the biggest losers. In that event, Bernie and his movement wouldn’t escape without paying a heavy price too. Their image and reputation would be badly tarnished. Much of the good will, enthusiasm, and promise that his candidacy generated could vanish in a flash. To brush off this possibility, as some do, is either naive or irresponsible.

Not everyone agrees, which come as no big surprise. In fact, many of his supporters say that Sanders should stay in the nomination hunt all the way to Philadelphia. Turn it into a floor fight at the convention, they argue. Any exit before then, they claim, would undercut his leverage on other matters being deliberated, not to mention any chance of securing the nomination. O’Lord, this too is misguided, in fact badly so.

To begin with, Hillary, barring something unforeseen, has a lock on the nomination. It is dreaming to think that Bernie has a viable pathway at this point. Admittedly, dreams have a place in politics, but only if they have some basis in reality. This one doesn’t. It’s pure fantasy.

Furthermore, the reality – not the dream – is that Bernie could drop out tomorrow and he would still have plenty of leverage at the convention on everything, except for who carries the presidential timber for the Democratic Party this fall. Again, that has been decided for all practical purposes.

Contrary to what some of Bernie’s boosters contend, his leverage doesn’t rest mainly on his delegate count. It stems largely from the legions of enthusiastic voters who supported him in the primaries and whose support Hillary needs this fall if she is to beat Trump. And no one knows this better than Clinton herself.

Finally, a refusal to concede the nomination to Hillary prior to the convention is the wrong fight to pick. Other fights are far more important. It will result in – not creative tensions (which are part of any broad, diverse, and dynamic coalition) – but sharp and lasting divisions at the convention and beyond, which will help no one – not Hillary, not Bernie, not their supporters, not the effort to defeat Trump, not the struggles to come in the years ahead.

Imagine what it will look like to tens of millions of TV viewers watching the convention (and what the implications will be for popular struggles going forward), if Bernie’s overwhelmingly white and youthful delegates are at loggerheads with Hilary’s Black, Latino, women, and trade union delegates over who the standard bearer will be. While the movement around Bernie is an incredible breath of fresh air and cause for optimism about the future, its potential will be realized only if it is able to build a “durable alliance” with the main class and social constituencies that are at the core of any transformational movement that has the capacity to effect a “new burst” of freedom, equality, economic security, ecological sustainability, and peace.

Right now most of those forces are attached to Clinton’s campaign, not Sanders’ movement. But that fact – especially as it applies to African-American and other people of color – seems to receive little attention from Bernie and his supporters. The energy, boldness, and imagination of youth, it goes without saying, is vital to the success of any movement and livable future, but it can’t substitute for the power, experience, and understanding of a broad multi-racial, male and female, working class-based people’s coalition.

One final thought of this wordy reply: uniting their two divergent streams of voters against Trump is the main strategic challenge as Bernie, Hillary, and their respective camps approach the convention. My guess is that Bernie, Hillary and the vast majority of their supporters are disposed toward unity, albeit not arrived at in a formal way, but rather in the course of a give-and-take debate, with a dollop or two of tension, and a good measure of creativity and compromise. Of course, everybody isn’t of that mind.

On the one hand, overly-zealous supporters of Clinton in the top (and lower) circles of the Democratic Party are inclined to freeze out rather than welcome Bernie and his delegates to the convention. And, on the other hand, the main organizing principle of too many of Bernie’s supporters is to turn up the temperature no matter what the circumstances or challenges. Politics for them is about nothing but militant and righteous talk devoid of any consideration of the larger dynamics, balance of power, and dangers of this moment.

Hopefully though, the tone, agenda, deliberations, and outcome of the convention will not depend on either of these two groups, but rather on what the two candidates – Hillary and Bernie – and the rest of their supporters do and say.

Hillary, if she is smart, will tip her hat and extend a hand to Bernie long before they meet in Philadelphia. And Bernie, if he’s serious about advancing a progressive agenda, will respond accordingly.