There is an enormous amount written about Lenin and the Bolsheviks, but for those who want a quick starting point, Britannica provides a summary of the Red Terror, which was initiated under Vladimir Lenin:

“The Red Terror was a campaign of political repression and executions carried out by the Bolsheviks in Soviet Russia, primarily during the Russian Civil War. Following their seizure of power, the Bolsheviks faced significant opposition, including from rival socialist parties and peasant resistance to food requisitions. In response to perceived threats, such as an assassination attempt on Vladimir Lenin, the Bolshevik government, through its political police force, the Cheka, initiated mass executions of suspected opponents. The terror also involved the taking of hostages and was a means to consolidate Bolshevik power and suppress dissent. The Red Terror resulted in an estimated 140,000 deaths.”

Or start with Wikipedia – not exactly a right-wing platform: