President Trump knows well the power of nostalgia. His whole campaign was based on convincing people he could bring America back to an earlier, happier time, when everyone had a secure job with great benefits, certain people (you know who I'm talking about) knew their place, and America stood tall.

But what if the earlier time he wants to bring us back to was actually a nightmare? That's what Trump and his party want to do on health care.

Appearing on ABC News' This Week on Sunday, Secretary of Health and Human Services Tom Price performed an important service in clarifying what the Republican Party is up to. Asked about the unified wall of opposition to the GOP plan to repeal the Affordable Care Act — from patient groups, hospitals, doctors, seniors, and even the insurance industry — Price replied, "It's really perplexing, especially from the insurance companies, because all they have to do is dust off how they did business before ObamaCare."

And what could be wrong with that? Well, let's have a little history lesson, for those whose memories of life before 2010 have gotten hazy. Because the truth is that how the insurance companies did business before the ACA is the whole reason we had a national consensus that we needed to reform health care.

To begin with, the perfect wisdom of the free market had somehow left 50 million Americans with no coverage at all — and the GOP health plan would get us back near that number. Then let's consider pre-existing conditions. Maybe your family has some of them; mine does. Nothing life-threatening — an old injury here, a bothersome condition there — but in the past it was enough to get us denied coverage on the individual market. If it didn't happen to you, it probably happened to someone you know. The ACA outlawed those denials, and while most Republicans claim they want to keep those protections in place, the bill the Senate is considering would eviscerate them. A provision written by Ted Cruz that was recently added to the bill would allow insurers to offer bare-bones plans that provide little if any real coverage, as long as they also offered a plan that was compliant with the ACA's mandate that insurance cover "essential health benefits" like hospitalization, emergency care, preventive care, and prescription medications. Health-care experts warn that it would create a two-tier system in which young and healthy people buy the cheap coverage and those who are sicker and older buy the more comprehensive coverage, quickly leading to a "death spiral" of skyrocketing premiums in the latter.

Which is why last week, America's Health Insurance Plans (the insurance industry's main advocacy group) and the Blue Cross Blue Shield Association sent a letter to Mitch McConnell saying of the Cruz plan, "It is simply unworkable in any form and would undermine protections for those with pre-existing medical conditions, increase premiums, and lead to widespread terminations of coverage for people currently enrolled in the individual market," adding that "As a result, millions of more individuals would become uninsured."

But that's just the beginning. Those low-cost plans Cruz and other Republicans want to bring back are often referred to as "junk insurance," and they're essentially a scam on unsuspecting customers. People are attracted to the low premiums, then when they have a medical need they discover — often at the price of financial catastrophe — that they have almost no coverage at all.

But hasn't the ACA led to huge premium increases? Actually, no. Premiums have risen, but what most people have forgotten is that before the ACA, premiums were rising at a much faster rate than they are now. For instance, according to the Kaiser Family Foundation, premiums for an employer-provided family plan rose an average of 63 percent over the five years between 2001 and 2006; over the five years between 2011 and 2016, the average increase was only 20 percent. The story on the individual market has been similar. "It would have been a lot worse if we had done nothing" may not be a politically effective argument, but sometimes it's the truth.

As long as Republicans are pining for what insurance was like before the ACA, how about recissions? In that particularly lovely insurance company practice, when people experienced a major illness or accident, their insurer would comb through their history to try and find a pretext to kick them off their coverage, just at the moment of their greatest need. During the debate over the ACA, one woman testified to Congress that when she was diagnosed with breast cancer and needed a double mastectomy, her insurer retroactively canceled her coverage because when she enrolled she neglected to tell them that she had once visited a dermatologist for treatment of acne. Her story was not unique; congressional investigators found that tens of thousands of Americans had had their policies rescinded. The ACA made recissions illegal.

Some people have forgotten that when you applied for insurance, you used to have to list every time you'd been to the doctor for years prior so that the insurer could decide if they wanted to deny you coverage. You don't have to do that anymore, thanks to the ACA; now they have to cover you no matter what, and pre-existing conditions no longer matter. But Republicans would return us to those bad old days.

And we should be clear that there are ways in which the Republican bill would make things much worse than they were before the ACA, particularly when it comes to Medicaid. Not only would the ACA's Medicaid expansion be rolled back, but they would convert the program to block grants, dramatically reduce its funding, and give states the "flexibility" to kick people off or cut back their benefits, which they're prohibited by law from doing now.

When the ACA was passed, smart Republicans understood that it would be hard to unwind, because it's much easier to prevent people from getting a benefit in the first place than it is to take it away once they have it. That's part of why their repeal bill is giving them so much trouble; the debate over health care has made Americans understand what they're getting and what it would mean for it to yanked back. So the next time you hear someone like Secretary Price tell you that repealing the ACA will be no big deal because things will just go back to how they used to be, don't forget what it really used to be like.