What will happen if Edinnaya Rossiya and/or Putin makes some huge mistake, and Russian public opinion turns against them?
We will elect "lesser evil", which is (by media) something like Prohorov.

I can ask the same question to USA:
"What will happen if Democrats makes some huge mistake, and USA public opinion turns against them? Which party do you elect?" (n years passed)
Ok, but...
"What will happen if Respublicans makes some huge mistake, and USA public opinion turns against them? Which party do you elect? (n years passed)
Ok, but...
"What will happen if Democrats makes some huge mistake again, and USA public opinion turns against them? Which party do you elect?" (n years passed)
...
I found it very convenient, yes.