Rumor vs Reality

The recently released Senate report clearly shows that the investigation began as a foreign intelligence operation monitoring Russian agents. Several Trump campaign operatives had significant contacts with those agents. The report also also had some harsh criticism for some FBI processes. The final word, however, was that the investigation was deemed legitimate.
References
New York Times: 8 Takeaways From the Senate Committee Report on Russian Interference
Wall Street Journal: Senate Panel’s Russia Probe Found Counterintelligence Risks in Trump’s 2016 Campaign