The facts are these (all according to undisputed reports by special counsel Robert Mueller, the bipartisan Senate Intelligence Committee, and many news outlets):
The Trump campaign eagerly and knowingly accepted overtures from the Russian government to provide dirt on Hillary Clinton.
Trump publicly asked the Russians to illegally steal and dump Clinton documents, and Russian intelligence promptly did exactly that.
The campaign and its associates had at least 100 contacts and probably more with assorted Russians, including (according to the Senate Intelligence Committee’s account) ones with ties to organized crime and Russian intelligence.
Trump’s campaign manager provided internal campaign materials to a business associate characterized by the Senate report and the U.S. Treasury Department as a Russian intelligence operative.
The campaign team, including Trump, was well aware of potential plans by Russia’s Wikileaks partner to dump stolen documents, kept close tabs on it, and tried to schedule and exploit that possibility.
Trump and his fixer Michael Cohen lied point-blank about Trump’s ongoing business dealings with the Russians.
Meanwhile, at no point did Trump and his people report Russia’s activities to U.S. law enforcement; instead, according to the Senate Intelligence Committee report, the campaign was “elated” by what it regarded as a “gift” from Wikileaks.
That the Trump campaign did all of those things and more is not seriously disputed.