The Democrats are threatening the change the filibuster rules in the Senate. The repercussion may be a significant response by the Republicans when they take control of the Senate. This may be quite soon if Nate Silver’s forecasts pan out. 

But perhaps the magnitude of the response can be quantified by examining history? Legislation has to be approved by the House, Senate, President and often the Supreme Court. How would a simple majority rule in the Senate have changed legislation?  Repealing Obamacare, civil rights, etc might be hard even with Senate majority rule. Cabinet and other appointments require Senate approval. How would a simple majority rule have changed personnel? John Bolton was a recess appointment at the U.N. – things would not have been different if he had been approved by Senate majority rule.  Etc , etc.

Probably someone has studied this already…