There is insufficient evidence to accuse the Trump campaign of criminal conspiracy with its Russian benefactors. However, “the social media campaign and the GRU hacking operations coincided with a series of contacts between Trump Campaign officials and individuals with ties to the Russian government.”
Read Mueller’s first public comments on the Russia investigation
These contacts were covered up by a series of lies, both to the special counsel and to Congress. Lying by the Trump campaign successfully obscured much of what happened in 2016. The special counsel in some cases “was not able to corroborate witness statements through comparison to contemporaneous communications or fully question witnesses about statements that appeared inconsistent with other known facts.” In particular, the investigation never did determine what happened to proprietary Trump-campaign polling data shared with the Russians.