I guess one metric of repression is what parties are represented in a legislative assembly.
For instance, looking at:
https://en.wikipedia.org/wiki/November_1932_German_federal_e...
https://en.wikipedia.org/wiki/March_1933_German_federal_elec...
https://en.wikipedia.org/wiki/November_1933_German_parliamen...
things are still looking healthy in Mar 33 (my metric: no party has more delegates than all the other parties combined; others will obviously use different metrics) but Nov 33 is completely out of hand.
Looking at:
https://en.wikipedia.org/wiki/State_Duma#Latest_election
the Duma at least has more than two parties, but isn't healthy by my metric. (the same occurs in the upper house)
When more repression arrives, either we'll see a Duma that's nearly 100% "ER and friends", or we'll see a Duma with the same parties but so ineffective that if Putin's horse were elected (it could easily commute from an office in the Moscow Manège?) it wouldn't be any worse than any other deputy.