Sure, there are. But Twitter is actively trying to work against it, and so far, in my personal experience I have not seen Hitler apologists on the site.
Sure, there are full fledged genocide deniers ( I have personally read tweets on Holodomor and Srebrenica denials), plus supporters of fascist regimes like in DPRK and Syria. Then there is the stuff like the BJP IT Cell tweeting their absolute worst.
There are Hitler apologists on twitter too. Along with pedos and groomers, racists and misogynists, among others. No, twitter doesn't remove them all either.
I personally haven't seen these as I keep my feed limited to tech news and memes but what you can do is click on "report"* And Twitter may take action. I have had bad experience myself with the reporting mechanism as it does not take action always on reported tweets. That I blame on the Twitter execs who do not have moderators who are properly aware of the region of the world they have to moderate. But broken as it is, it still works.
Parler has a report button from what I have heard but it is only for show. And from the former CEO Matze's own words, they allow all constitutionally allowed speech which unfortunately opens the doors for actual Nazis to flood the site with their hatred.
Sure, there are full fledged genocide deniers ( I have personally read tweets on Holodomor and Srebrenica denials), plus supporters of fascist regimes like in DPRK and Syria. Then there is the stuff like the BJP IT Cell tweeting their absolute worst.