Three weeks ago, Sen. Bernie Sanders (I-Vt.) introduced a Medicare for all bill with some of Democratic senators, which were a third of the Senate Democratic caucus. Just two years earlier the senator had introduced another such bill with zero cosponsors.

The latest introduction was hailed by some as an impossible achievement. After having achieved what the naysayers and many Beltway insiders admitted was the impossible, they quickly pivoted to the impossibility of moving the ball forward legislatively.

For those of us who supported Bernie Sanders’s presidential bid in 2016, this was nothing new. We spent a year confronted by all the impossibilities — he’s too left, he’s too old, he can’t raise money, he’s not coiffed enough. As he started to move in the polls from around 3 percent, they said his support had a cap.

When tens of thousands showed up for rallies during what the media dubbed the “Summer of Sanders” they said those crowds would not turn into votes. When he earned the votes of millennials of all races and eventually voters under 40 of all races, they said his appeal was too narrow. Even in the face of demonstrated success (winning 23 Democratic primary contests), raising almost a quarter of a billion dollars averaging $27 each, and demonstrating his remarkable stamina by carrying on a daily schedule that had the youthful media corps dragging -— there was always another hurdle and that hurdle was always most certainly impossible.

Nowhere was that false narrative louder than the criticism of his bold agenda as pie in the sky, rainbows and unicorns, or free ponies for everyone. Guaranteeing health care for all, raising the minimum wage to $15 an hour, and providing tuition-free college were, at best, empty promises with no hope of success and, at worst, they were deliberate flim-flam. They were, after all, “impossible.”

Recent polling now shows escalating support for a Medicare for all health care system. Raising the minimum wage to $15 an hour is now the position of the Democratic Party. Target has announced it is moving toward a $15 minimum wage for all its workers by 2020. And tuition-free college is advancing in a number of states including a new two-year community college program in Rhode Island. All impossible! All happening.

That is what Bernie Sanders dubbed the Political Revolution. It’s not about a single leader. It is about a movement of millions Americans who want a better life for themselves and their families, and leadership that gives voice to those universal aspirations. It was pooh-poohed by so many cynical talking heads and defeatists in the establishment – including some in our own Party. They didn’t get the Political Revolution then and they still don’t.

This horse-blinded conventional “wisdom” played out in the last week when the Republicans, like Dracula rising yet again from the grave, tried once more to strip millions of their health insurance by gutting the Affordable Care Act. The Republican talking points tried to conflate saving the ACA with efforts to create a Medicare for all program. Many Washington insiders panicked. Hadn’t Bernie Sanders handed the GOP an argument that would allow them to strip away the ACA’s considerable gains?

Never mind that Bernie Sanders has been the active point person for the Democratic Party in fighting the Republican “repeal and replace” efforts. The senator organized over 170 events in support of the ACA, including many in so-called Trump country. As one outlet observed , “No one in the [Democratic Senate] caucus has put as much skin in the fight against repeal as the Vermont senator, who kicked off the party’s health-care resistance with a rally in Michigan a week before the inauguration and has been touring the country and in opposition pretty much non-stop.”

The carping reached a boiling point when Sens. Sanders and Amy Klobuchar (D-Minn.) agreed to a CNN debate against the sponsors of the latest Republican repeal bill. Surely, Bernie Sanders was playing right into the hands of his enemies by letting them frame the fight as Repeal and Replace vs Medicare for all.

As it turns out the Sanders/Klobuchar tag team pretty much mopped the floor with their opponents who, ironically, spent much of the time making the case for Medicare for all by highlighting the abuses of private health insurers and the pharmaceutical companies.

Those with less fortitude missed the point — that one can lay out a bold vision for the future while defending the progress that has been made. They don’t get that the limit of what’s possible is the beginning of what is impossible and you only achieve the maximum of what’s possible by testing that ever-changing limit. Protecting hard fought gains while always pushing forward is the story of all the major successes of Democratic Party in the modern era.

Each generation builds on the progress made by its predecessor. FDR began the process by transforming America with Social Security and a host of other reforms. But he could not achieve his goal of universal health care. Truman tried next without success. LBJ created Medicare and Medicaid. Then came the CHIP program. President Obama created the Affordable Care Act. Each was a move toward universal access to health care. And the changes each iteration made to previously existing programs was not a repudiation of the previous advance but a fulfillment of the promise that today’s gains are the building blocks for tomorrow’s. The same is true for Medicare for all.

In every case outlined above, these Democratic leaders had to contend with the forces of reaction simultaneously working to destroy what had been achieved and working to prevent further progress. It wasn’t just from the other side of the aisle. Each of these Democratic leaders faced opposition from some of those forces in our own Party.

FDR’s fights within the Party are legendary. History will also remember the terrible role played by Sen. Joe Lieberman (I-Conn.) and others in torpedoing key elements of the Affordable Care Act that President Obama supported like the much talked about Public Option. In that sense, not much has changed in the current fight for universal health care.

For all those despairing in these rather depressing political times, the last two weeks should offer a ray of hope that it is in fact always darkest before the dawn. Despite the defeatism among too many on our own side, and the ceaseless attacks we will face from the Republicans and the billionaire class they represent, the path ahead for real progressive change is clearer and clearer. Sadly, most in the establishment still don’t get it. To them, it’s always impossible and that is why they fail. The don’t see the political revolution that is happening right before their own eyes.