It may have held the country back IN YOUR OPINION, but that is not a fact. Just b/c you want us to go a certain direction doesn't mean the majority of the country wants the same thing.
Sure, I suppose these are all opinions. For example, people out there think things would be better if the "south" rose up and brought back the Confederacy, white supremacy, etc.
So, then you talk about what the majority of America wants. Not sure you want to go down that road, because that world would like more like what I have been describing than what you are fighting for. The problem is, we don't have national referendums like real democracies that allow us to vote on particular issues. If you are interested in what real democracy looks like, I suggest you read "Democracy and its Critics" by Robert Dahl. It's an incredible read.
Our democracy is tainted in critical ways, and reforms are needed. First, our system is based on law, not on majority rule. Second, the two party system itself robs people of legitimate representation. We essentially have a "winner take all" system. A tiny majority of people vote GOP in Florida? 100% of them are governed by GOP. Other countries with more robust democracies have better forms of representation. Second, big money in politics isn't compatible with legitimate democracy. That's why Citizens United was such a big issue.
And finally, the political parties themselves create a bizarre voter where you have to accept a party, all or nothing, because we can't vote on particular issues like in Switzerland. And they are pretty much universally entrenched as a team. Very few break ranks. What if I want to expand social security, but don't support abortion? I don't have a candidate. What if I want to have tuition-free education, but want no intrusion on what I believe are 2nd Amendment rights? I have no candidate. I have to accept the entirety of their policy positions to get the one thing that is important to me.
I am sure you have heard the term "single issue voters"... It is estimated that a very large portion of the population are single issue voters. Which mean, they likely sacrifice many things they want in exchange of a particular issue that is especially important to them. This is flawed.
Sorry, I was ranting.... anyway... Yes, just like it is an opinion that white supremacy is the best way to go, it is also an opinion that Trump and those who think like him are taking America in the opposite direction. Going backwards, not forward.
However, consider this... What is a "conservative"? What does that mean? Naturally, it means to "conserve".. Not change. So let's say one administration made a lot of significant changes (like FDR and LBJ), and the conservative administration comes in and undoes those changes, they are putting it back the way it is originally. I would call that going backward, because if you never change anything you know what happens? Nothing.
Many of the "conservative" policies aren't trying to take the country in a new direction as much as they are trying to put it back the way it was at some other point in time. Such as... before abortion. Before social security. Before Medicare. Before Obamacare. Before environmental regulations... Before gays were socially acceptable... etc.
We'll see. Generations change. People change. Culture, economics, the general world environment all change. People thought when the children of the 70's grew up there would be a big shift toward liberalism. As that generation grew up, that shift never really occurred. Much like every other thing on this planet, there is an ebb and flow. Once we start going too far one direction, it flows back the other. If you think this country is ever going to be run like Bernie Sanders wants to run it for more than a couple of terms, you are crazy. It won't happen. It'll turn right back towards conservatism. That's the way of the world.
As you said, we will see. I happen to believe that we are in the last real generation of expansive conservatism. Remember, our older generations are basically from a different world (I can think of some comments my own grandparents make that are FAR from socially acceptable). And the generation below them as well. They share little in common with the middle aged and younger generations. The world is trending liberal, and America will eventually catch up.