Maybe, this will help understanding:
http://www.washingtonpost.com/opinions/how-russia-props-up-putin-in-the-polls/2015/01/30/0302bea8-a59e-11e4-a7c2-03d37af98440_story.html
If it's not 80%, what is it or should it be?
The 'MSM' is very powerful. They can reduce Nixon's 60% landslide to ~40%, 1st Bush after defeating Sadam, from 90% to ~40%.
What has Putin at 80% is not their MSM but the fact that he is country 1st. The Ukrans and Russians on both sides of the border probably know more of what's going on than we do or what we are being told.