I like the history channel,how about you ?
Here they are listing the history of disputed elections,nothing new.
https://www.history.com/news/most-contentious-u-s-presidential-elections
Are we forgetting about 2016 where the entire voting system may not have been attacked but there was 4 years and millions of dollars trying to overturn it,not much difference there.
One could argue the voting system at that time was in question,maybe HC conceded so quick because she was afraid that the system was rigged and people would have found out.
Just like with the current one,they did not figure the wildcard would be there in Trump.