No. You need the majority of stake in any point of time past, to forge all the history of the future from that point of time on. So any group who ever had 51% of the currency/votes/etc. can rewrite the history at will. Or any group that can coerce any group at any point of time. There is also no mechanism to keep track which of the forks is the correct one.
Yes, there is a mechanism to keep track which fork is correct. It's called Economic Clustering. But it will likely never be utilized, as getting private keys of 51% coins seems a much more insurmountable task than coercing 2-3 biggest PoW pool operators to follow a certain agenda. But EC will be there just in case, so yes, nodes can know which fork is correct and be in consensus. There is also a penalty in EC for forgers who forge on an incorrect fork.