There's no evidence that the Democrats did anything with Russia. Not the same with the Trump campaign however. a couple of hundred contacts during the campaign in 2016 but not enough evidence to prove a conspiracy beyond reasonable doubt due to Trump people refusing to testify, taking the fifth, destroying evidence and so on.
There's no evidence that the FBI or anybody else spied on the trump campaign. The best bullshit claim the Trump people can make was that the FBI applied for a wiretap on Carter Page, a man who had worked for the Trump campaign for literally a couple of meetings and had had nothing to do with the Trump campaign for six months before they applied for the warrant, a couple of weeks before the election. They'd previously applied for wiretap warrants on Page in 2014 and had good reason to apply for the October one which was renewed after six months meaning it was producing evidence of criminality.