Like most Bernie Sanders supporters, it was hard for me to watch Hillary Rodham Clinton take the stage on Thursday night to accept the nomination of the Democratic Party, while Bernie sat in the crowd looking on, unable to conceal his exhaustion and dejection.

As Bernie said, there is a winner and a loser to every contest, and he lost this time. But it is impossible to escape the feeling that he could very well have won, if the Democratic establishment had not undermined him at every step, aided and abetted by the establishment media.

What would this election season have looked like, if we had two outliers, Donald and Bernie, duking it out?

We’ll never know, because this time around the center held—the center represented by the centrist Hillary Clinton.

As Bernie has been saying, it’s clear that his revolution has pushed Hillary to the left. We heard it in her acceptance speech, where she said loud and clear that she stands for free public education for kids from families making $120,000 or less. She said, somewhat less clearly, that she stands for “a living wage,” and for student loan relief. We know that she believes in universal health care. She said over and over again that she will work tirelessly to create more good jobs in America…with “clean energy jobs” a phrase repeated more than once in the speech.

I took away two important impressions from her remarkable convention performance last week.

One, she did a brilliant job at pitching herself as a leader. While she does not have the oratorical gifts of Barack or Michelle Obama, she looked more comfortable on the stage than I’ve ever seen her, and she spoke with a believable conviction about her ideas and vision for the country. She looked fierce and glad and on fire to sweep away that cracked glass ceiling once and for all, and hallelujah for that!

Two, it was clear from her speech that this is a leader who can learn, grow and change. While she has principles and commitments that have never wavered—women’s rights are human rights, for example, or all children deserve quality education and health care—she is also capable of shifting her ideas as she learns more about a given issue. This has earned her a reputation of “shiftiness,” but I am coming to see that as unfair. We want a leader who listens, thinks for herself and lets her opinions evolve.

For example, her stance on the invasion of Iraq, or the TPP treaty: initially she supported both these moves, and now she understands that we were led into Iraq on false premises, and that the TPP is not going to improve the lives of ordinary people—certainly not in the US, and maybe not anywhere in the world.

Seeing her position on these issues evolve over time gives me hope that she will also be the kind of leader who, as Bill McKibben wrote in a recent email to supporters, we can “pressure” to move towards the left of the center space she holds.

Like Barack Obama, Hillary Clinton is striving to represent “all Americans,” and let’s admit that that category includes the frackers and the assault weapons enthusiasts as well as the environmentalists and the peaceniks. For a leader, holding the center ground in the midst of such fractious, strong-willed constituencies can be exhausting, especially as you are doomed to fully please no one.

But this is the kind of leader a big, complex democracy like America needs. Someone who can sit calmly in the center of the storm and keep the ship of state moving forward, as President Obama has done despite the obnoxious Republican obstructionism in Congress.

Hillary Clinton has the advantage of being deeply steeped in Congressional politics, as well as gubernatorial politics and international politics—as she reminded us in her convention speech, she is no stranger to public life. Almost twelve years as the wife of the Governor of Arkansas, eight years as First Lady of the United States (and not the kind of first lady who just bakes cookies and chooses china patterns); eight years as Senator of New York; and four years as Secretary of State.

As President Obama said in his own super-moving convention speech, there has never been a candidate as well-prepared as Hillary Rodham Clinton to assume the presidency of the United States.

I believe that she will be an effective leader who will be able to get things done in Congress. It is up to us, her constituents, to let her know loud and clear how we want her to represent us.

That is where the Bernie revolution must get back into gear. We can’t sulk on the sidelines and refuse to vote! Now more than ever we must engage relentlessly with the powers that be, rejoicing in successes (like pushing Wasserman Schultz out of the party leadership) and continuing to let the Democratic Party know that if it wants our votes, it has to walk the walk of its democratic principles.

Hillary is right, “we are stronger together.” The Democratic Convention (unlike the RNC) showed an inspiring range of people coming together—people of all ethnicities and religions, all kinds of people standing together under that big tent to participate in steering our country into safer waters.

I was so glad to hear Hillary say clearly that she intends to work through policy to ensure that the rich, including Wall Street and corporations, start standing with the vast majority of Americans who are struggling to make ends meet. Clearly, she has heard Bernie Sanders and his millions of supporters. We will need to hold her to her promises.

Hillary Clinton is a transitional figure between the old guard represented by her husband, among many others, and the new millennial wave represented, someone bizarrely, by that old white guy (and Jewish Democratic Socialist), Bernie Sanders.

We are in the midst of a seismic cultural shift, not just in America but in the world. The era of the global free trade cowboy is coming to an end. The globe has become too small and the Internet connections too penetrating to allow violations of human and environmental rights to be perpetrated with impunity. The TPP is a last gasp of this old regime (and why Obama has been supporting it is beyond me, it’s a serious flaw that I hope he will come to regret).

We are moving into a time when the local truly does become the global; when each of us sitting in our homes is aware of how intricately we are connected, all across the world. Next step, to fully mine these connections for the potential they hold to mobilize each of us to stand up for what we believe in, and join hands with others who share our vision of social and environmental justice, irrespective of archaic artificial boundaries like nationality, ethnicity or religion.

No single leader can do this for us. We need to make it happen ourselves, where we live—and this means in our local, physical communities as well as in our virtual communities online.

The Republicans are mobilizing on their side, and they’ve got a leader they deserve.

In Hillary Clinton, we have a leader who will hold the center for us as we do the essential work of social change, transitioning our global human civilization from a “dominate, exploit and destroy” mentality to a “nurture, connect and prosper” mentality.

Is it an accident that our transitional leader happens to be a woman? I think not.