Parallel construction requires you to acquire the same evidence in a lawful manner that is not "tainted" by the inadmissible evidence. If they cannot find admissible means to accomplish this, they cannot use the evidence in court.
It's not some magical way to make up evidence like some seem to think.
Once they know for sure they'll find something, it's easy to bootstrap a stop and search from "little white lies", about subjective or unverifiable things. (The car was 'erratic'; there was a 'smell'.) The lies no longer have any risk, when they're only used to set up sure things.
After the search hits paydirt, the petty fabrications used as a cover story to create probable cause seem credible, and the perp's denials flimsy and self-interested. And since the prosecutors and courts only ever hear the surface story – the original illegal evidence is never revealed to them – they don't even know they're looking at a "parallel construction".
I definitely don't believe that "parallel construction" should become the norm.
But at the same time, I have faith in the decision the federal appellate courts (you could claim that's naive, but I do).
In the long term, I hope that any parallel means to make "admissible" evidence unallowed should be excluded. But until that is legally determined, I honestly do support common law / American jurisprudence. And if people continue to make their opinion heard, I believe that it will change.
My father is an attorney who works for city and county governments. My grandfather is a state judge. I don't claim that either of them exceptional to the current debate, but I strongly believe that jurisprudence will evolve similarly to public opinion.
If I've learned anything, it's that both of my family members honestly try to prioritize their government oversight/trial work over personal opinions. To the point of of heated arguments with my family and I.
And I'm not a lawyer, so I cannot refute several of their constitutional arguments. But I similarly can't effectively argue against their options in "traditional" cases.
I will say without qualification that many cases can only be fairly adjudicated with seemingly "neutral" opinion. And that any opinions about transparency or openness put current law is not necessarily worthwhile. I may not agree with their logic, but I respect the judicial precedent.
For that reason, I hope far more pressure is placed on Congress than the Judiciary ( since one can define standards, and the other must obey the higher court decisions) for a fast-changing, judicial change. (really, I'm waiting for the next generation of judges to set the points of discussion).
Recent documents, indicating DEA/IRS agents were trained to hide the original surveillance evidence, suggest even the prosecutor might not know the true genesis of a particular bust.
The real original evidence is not discussed. Only the (sometimes very "lucky") later stop, suspicion, search.