Are supermajority reductions a root cause of our current political climate?

In our political system, decisions are made using either a simple majority or a two-thirds (supermajority) vote, depending on the action’s significance and constitutional requirements.

Over the past few decades there has been incremental flipping of supermajority decisions to simple majority decisions by. Are these decisions largely to blame for the evolution of the identity politics and partisanship we face today? Have they contributed more the public perception of illegitimate rule than we care to admit?