Be nice.

I think he is commenting on the obvious fact that politicians do not like to blame themselves for the problems they create. It looks bad and is bad for polls.

This whole "right-left-shift" paradigm is nonsense.

If the base moves so far left that their original position is now considered far-right,

then you still have a relative right-shift.

Howcome nobody ever questions said extreme left-shift of the base?

because left is "correct" and right is evil

Right, sums up the political discourse of our time.