Having an American opposition research company conduct opposition research—as both the RNC and DNC did with the Steele dossier—isn’t illegal though. The issue with Trump, and the reason that the FBI and then Mueller investigated, is because his campaign seemed to have knowledge of illegal Russian hacking, communication with Russia about it, and received the benefit of it, which could possibly be a violation of federal law, a felony.
Yes. I get it. It's the Dems catching the vapors that I don't get (well... I do get it, but I'm not really willing to play along, even for the purposes of critiquing Trump). They worked directly with the Russians to gather info on their political opponent, for political advantage, and through clear communication with Russian nationals.
When it comes to Trump, what does and does not fit within legal boundaries really does seem to shift pretty dramatically based on pretty difficult to parse out distinctions. He was also charged with conspiring to influence the election for paying hush money on a politically damaging story. I mean, that's just standard politics from where I stand. A campaign's whole raison d'etre is to influence an election, and one of the major ways it is done is through the control of information. But there's some small nuanced detail there that makes it a felony violation (or 34 felonies) that every other campaign has somehow managed to avoid.
Ditto for the classified documents. Biden has classified documents that he had zero clearance to have removed as they went back to his time in the senate, and Trump has classified documents that he did have clearance to remove as president but did not return. That detail is the difference between "nothing to see here" and "throw him in prison."
I know it comes off as a defense of Trump when I write these sorts of things, but I honestly have no doubt that the guy plays fast and loose with the law and has all his life but gets away with it due to his wealth and power. I don't think he's a good man, and he's a flat out ridiculous president.
Nevertheless, a part of the reason why he won the election is because weighed in the balance the American public was more inclined to believe the lawfare narrative than the narrative that Trump is sooooo different from anyone who has come before that he managed to commit 80 or 90 felonies in a few short years where no other president in 230 years has ever committed even a single one.
On a related note, I find it hard to believe that on a political level Trump will be the type of president who draws more people to his cause. The heavy odds on favourite outcome is that the country swings back dramatically to the Democrats in 2028. That's a good thing... except that it will probably result in the Dems coming away without learning anything.