At this week’s convention, we’ll be reminded that elections matter—and they do. But electoral victories, though necessary, are never sufficient. Uprooting inequality and restoring prosperity will require much more. Last week, we got an important reminder of the importance of grassroots organizing. It came from the president of the United States.

During an “Ask Me Anything” session with readers of the website Reddit, President Obama lent his personal support to the effort to amend the Constitution to reverse the Supreme Court’s devastating Citizens United decision.

“Over the longer term,” said the president, “I think we need to seriously consider mobilizing a constitutional amendment process to overturn Citizens United (assuming the Supreme Court doesn’t revisit it). Even if the amendment process falls short, it can shine a spotlight [on] the super-PAC phenomenon and help apply pressure for change.”

(Other campaign officials had previously expressed support.)

These are welcome words. First, because (as I’ve argued here and elsewhere), we can’t become a more perfect union as long as our elections remain playthings for self-interested corporations. As Public Citizen puts it so well: Democracy is For People. (And as Lee Fang reports in the current issue, if you think post–Citizens United Super PACs are bad for our democracy, trade associations are even worse.)

Obama’s words send a strong signal where we need to go. But they’re equally important for what they say about how we get there.

In becoming the nation’s top constitutional amendment endorser, Obama reminded us that he remains our first community organizer president. From the beginning, some of the smartest minds in the movement to overturn Citizens United movement have seen the amendment process as an organizing instrument, not just a legal lever.

Obama’s support for an amendment puts him on the right side, with over a hundred municipalities who’ve moved to amend, and against the plutocrats who want to buy our elections. It sharpens the contrast between a president committed to “We the people” and a challenger convinced that “corporations are people.”

And it’s heartening to see the president’s personal step forward on the issue echoed in his party’s new platform, which backs “campaign finance reform, by constitutional amendment if necessary.”

But Obama’s statement also raises the question, Given that the president gets how social movements make change happen, why does he only sometimes act like it?

Obama’s 2008 campaign paid repeated tribute to the power of citizens acting in concert against injustice. Indeed, he led an effort that captured the feel of a true social movement in a way few presidential campaigns do. And he won.

It was easy to believe, in the heady days that followed, that we would see a new kind of president embrace a new kind of presidency: one that nourished and encouraged robust citizenship, that mastered effective inside/outside symbiosis and marshaled a grassroots army against business as usual.

Instead, Organizing for America was shuttered as we knew it, shunted instead into the Democratic National Committee. Righteous anger at Wall Street was triangulated by the president and his chosen Treasury secretary, rather than being embraced as a force for change. And the transformational promises of candidate Obama gave way to the transactional politics of Chief of Staff Emanuel.

As the Washington Post’s Peter Wallsten observed in a masterful piece in June, Obama’s relationship with progressive activists has “moved from great expectations to tense confrontations to pragmatic coexistence as the next election approaches.” Wallsten profiled how immigrant rights and LGBT groups—with tactics and stances derided by know-better insiders—forced Obama to go farther and faster than he’d claimed was possible.

Too often, Obama refused to confront obstructionist forces intent on making him a one-term president. And instead of marshaling people to overcome the lobbyists and forces of corporate power determined to dilute and gut his signature reforms, he let his staff hem in his ambitions, and his base. Now he’s paying the price, and so are we: an under-stimulated economy, a narrowed sense of hope.

And yet, as convention season reminds us, a Romney/Ryan victory would spell full-spectrum disaster.

An Obama victory in November would bring few guarantees. We all know now what should have been clear then: no person makes change alone. Formidable obstacles stand in the way of progress. Without grassroots pressure and organizing, corporate power over both parties will suffocate possibilities every time.

But a second term presents an opportunity for change, and a revealing choice for the president: succumb to business as usual, or embrace the audacity of a bolder politics?

Movement pressure has already moved the president—both on policy and on vision. Witness his barn-burning December speech in Osawatomie, Kansas, setting forth how “the basic bargain that made this country great has eroded.”

Was Obama’s first-term approach inevitable? Or will a second-term Obama govern as not just a horse-trader in chief, but as someone who understands the power and necessity of movements and organizing?

“One of my fundamental beliefs from my days as a community organizer,” Obama said in 2008, “is that real change comes from the bottom up.”

Hope—not rosy optimism but the belief that hard work and commitment makes change—springs eternal.