The predigested narrative of the Democratic presidential primary frames the battle between Hillary Clinton and Bernie Sanders as one pitting the pragmatist versus the dreamer, the grinder with the knowledge to work the levers of the system versus the head-in-the-clouds visionary.

Lately, several mainstream liberal commentators have taken to siding with the pragmatist, painstakingly explaining to their readers the importance of preserving existing gains in a time of partisan warfare, and dismissing Sanders’s ambitious platform as misplaced and foolish. Incrementalism is a reasonable ideological preference. But the hot rhetoric and the need for Manichean imperatives that characterizes campaign season has intensified the attacks on Sanders, painting him as a political dilettante who doesn’t understand how Washington works—and, by extension, suggesting that anyone in government with big ideas is doomed to failure and would be better off going along to get along.

That’s where this otherwise typical campaign back-and-forth strays into dangerous territory. When you saw off every policy to what falls into the immediate range of possibility at the present moment, you give supporters little reason to organize behind your ideas. More important, you neglect the creative ways in which those seemingly unrealizable goals can be realized, no matter the situation in Congress.

Maybe you’ve heard the one about the community health centers.

Originated in 1965 as a Great Society reform from the Office of Economic Opportunity, these neighborhood medical clinics provide integrated medical treatment and dental care to low-income and rural patients nationwide, regardless of the ability to pay. No two community health centers look exactly alike. But in general terms, they look more like the socialized medicine of Great Britain’s National Health Service than a single-payer program like those of Canada or France. Federal, state, and local grants fund the doctors and clinic personnel; the clinics refuse nobody for insufficient funds or lack of insurance; some even pick up and drop off patients at their residences.

From two demonstration projects, community health centers have grown to 1,300 networks in 9,200 locations, serving 23 million patients in 2014. As the National Association of Community Health Centers puts it, “In communities fortunate enough to have a health center, fewer babies die, emergency room lines are shorter and people live longer, healthier lives.”

And why do community health centers represent such a robust part of the health safety net today? Bernie Sanders.

In a well-known incident confirmed this week by Tierney Sneed at Talking Points Memo, Sanders made community health centers his cause in the Affordable Care Act debate, ultimately securing $11 billion in mandatory funding—instantly doubling the appropriation, which was previously made only through the discretionary budget. The number of patients served jumped from around 10 million in 2000 to today’s 23 million.

The way Sanders made this happen demonstrates how pushing big ideas outside the bounds of the possible can lead to tangible results, in ways that cautious centrism cannot. 

The Affordable Care Act process, at least in the Senate, involved individual senators carrying certain pieces of the bill. Those senators could use the leverage afforded them by the razor-thin margins required for passage to force their favored items into the final product. Some used this power for ill (see Joe Lieberman scotching the Medicare buy-in), some for parochial needs (like Chris Dodd getting a grant for a medical school in Connecticut). But others insisted upon what became fairly vital pieces of the ACA’s infrastructure. Al Franken was synonymous with the medical loss ratio, mandating that insurance companies spend a fixed amount on actual care rather than overhead or executive salaries. And Bernie Sanders made increased community health center funding the condition for his vote.

The relatively small $11 billion investment—a rounding error in the overall bill—gave a lifeline to millions of new patients, now able to obtain primary care (not to mention creating tens of thousands of health-care jobs). Community health centers actually save the overall system money, by limiting the use of emergency rooms as primary care locations and increasing take-up of preventive care. Without the funds, patients in states that expanded Medicaid under the ACA would find it difficult to access care because of doctor shortages and because many don’t take Medicaid; community health centers increase the supply of providers willing to see Medicaid users. The upshot: one of the nation’s bigger socialized medicine programs (which include Tricare and the V.A. system) helps sustain one of the bigger single-payer programs.

The program has been so successful, in fact, that several Republican senators, opponents of the concept of universal health care, have quietly requested additional funding for community health centers. When community health centers faced a funding cliff in 2015, Republicans Roger Wicker (MS), Shelley Moore Capito (WV), Mark Kirk (IL), and James Lankford (OK) fought to fix it, alongside Sanders. President Obama just added $500 million in funding this past September, with funding set at the Sanders level through 2017.

Among other things, this little story should put to rest the hyperbolic complaints about Bernie as a hippy-dippy dope shouting into the wilderness, with no ability to advance his hopes and dreams. Sanders, then and now, preferred full-blown single-payer; he tried and failed to get a vote on it during the ACA debate. But when he saw an opportunity to use his power, he exploited it—building a program that accords very well with his social democratic principles, despite all the countervailing forces in American health care that compel reformers to aim low. If anything, progressives should want a proliferation of lawmakers with the same perspective as Sanders—striving for big change with the skills to recognize advantages and actualize them.

When big ideas go mainstream, they also reinforce how government can work to people’s benefit. Community health centers have become an irreplaceable part of America’s health care infrastructure. Forward-thinking cities like San Francisco use them to provide accessible coverage to every citizen, in a single payer-like hybrid. Los Angeles is working on the same thing. Every time a new center opens, like this one in Asheville, North Carolina, more people get the security of knowing they can get help when they need it. And they get a little more faith that government can provide basic services, and commit to the belief that nobody in this nation should want for treatment when they’re sick.

Whether Sanders’s successes in the Senate translate into the skills needed to be president is a question for voters. But who wins the nomination matters far less to me than keeping the promise of big change alive. The recent flood of savvy takes about the dangers of Sanders’s “revolutionary” ambitions dampens any outbreak of inspirational politics, and tells hopefuls that possibilities for beating the entrenched system can never and do never exist. It plays to a kind of hard-bitten realism, but it creates a box around hope, narrowing the range of acceptable policy ideas to an absurd degree. And as the community health center story reveals, it’s just wrong as a factual matter. 

The key to making progress in a polarized era comes with having more ideas available on the shelf when opportunities arise. It’s how an outrageous handout to big banks that lasted for over a hundred years suddenly got cut, with Mitch McConnell stealing the idea from the Progressive Caucus budget. It’s how the entire student loan system was overhauled as an add-on to the ACA, largely because of outside pressure and one senator taking a stand (in that case, Tom Harkin).

There’s a point at which you can manage the base into oblivion, and jump from dismissing Bernie Sanders to dismissing the largest wing of the Democratic Party. What’s more, telling a new crop of progressive legislators, from Zephyr Teachout to Elizabeth Warren, that they must content themselves with the art of the possible, and back off big ideas, is not only bad politics. It’s bad policy.