So this began as a reply to a comment but got way too long.
The comment expressed concerns that the policies of Bernie Sanders were too radical and untested. That was combined with a desire for baby steps towards our progressive vision.
I start with the idea that many if not most of his policies have been implemented and have been working in other countries for decades.
I agree that small steps are reasonable. Heck, if we want faster change we can still use small steps but take them more quickly as a particular approach is proven.
But I think much of the current hesitation to endorse change, at least by we who are middle-aged, is due to a gun-shy instinct from the 60's.
Here's my interpretation of what happened:
There were tremendous societal changes in the 50's and the 60's (not to mention the 30s and 40s).
Unusually, many of those changes came from legislative action rather than activism, perhaps stemming from a progressive New Deal/post-war perspective in both parties (boy do I wish Eisenhower was still around to straighten the Republicans out). So the rules changed quickly but society changed more slowly.
Resistance to change built up in the 60's but national politics remained more progressive, at least until Nixon.
At that point, every stop was pulled out by conservatives, from Nixon to the Koch's Bircher father, to reverse the progress made.
It's not coincidence that so many problematic trends today started in the early 70's (increasing incarceration rates, "productivity" [quoted because, for individual workers, it was wage theft], demonization of liberals, wealth and income inequality and declining union membership).
But they didn't stop at legislative remedies. They knew they needed to win hearts and minds. Thinktanks sprang up funded by billionaires determined to discredit progressive policies. Worse, they worked to discredit progress itself.
Those that were disquieted by the changes (which were likely the majority at the time) were easily persuaded to react against those bringing change. Ironically, I think the backward slide was possible because of the progress made by the government in the 50's and 60's. It was easier to be complacent in the 70s that everything was going in the right direction, but maybe just a little too fast.
The 60's and 70's saw a boom in activists fighting for progress on all fronts. So it was natural that the body of activists would be targeted for especial attention by those wishing to halt progress.
Ways to discredit those activists were deployed at all levels of social life, and any time one spoke out there was an army of letter writers and spokespersons to disparage progressive statements. (BTW, that is still going on today, with even the US military employing hit teams to respond in papers and on social media whenever a meme they don't approve of begins to spread).
Now, another irony I've seen is that some of the most radical of activists on one side of the political dial can to flip to the other end when their goals are frustrated (e.g. Paul Wolfowitz started out as a Marxist). Sadly, that places those who know a movement intimately in a position to best attack the movement at the very time that their defection reduces the intensity of activism.
So the attacks and disparagement continued and accelerated into the 80s. It got so bad, Bill Clinton won a "liberal" victory by declaring the era of big government was over.
Thankfully though, Bill did restore some credibility to the left wing by governing in a fiscally responsible manner and even moved us back towards some socially progressive goals. Unfortunately, that was accomplished while a whole host of other progressive goals were rolled back.
So here we are today. The needle is swinging back towards a progressive vision. But we are still left with a case of Stockholm Syndrome. The groups that disparaged and sidetracked the progressive movement have convinced us that debt, crime, and social dysfunction are the fault of progressives.
Fortunately for us, the truth is otherwise.
The changes wrought in 60's did make many (perhaps most) people feel uncomfortable, and progressives are responsible for that. And that was the fuel that made it possible for reactionaries to lead a backlash against progressive policies. Further, we didn't stand up and counter the thinktank memes effectively.
However, look at any one of the social ills (debt, crime, breakup of families, ...) and you'll see they are the direct result of conservative policies that pursued punishment and austerity in the interest of drowning progressive government in a bathtub while padding the bank accounts of the wealthy and privileged.
So, I think your caution is reasonable. It's been a rough road for liberals and progressives over the last 40 years. But do explore the specifics of your fears You may find much of it is the result of being disparaged when showing concern for the poor or support for the marginalized.
But the times are a-changing, and we're well familiar with their tricks now. We're not as vulnerable to their ploys, and the public at large is not as credulous in the face of right wing talking points.
I think we're getting close to the point that the average person can look at the other countries that have comprehensive social services and a decent economy and say, "Hey, why don't we do that".