Should the Senate draw a line at the notwithstanding clause?

The question is not whether the Senate can exert its constitutional powers, but when and how. And motion tabled by Sen. Peter Harder suggests at least one answer to the question of when.

Should the Senate draw a line at the notwithstanding clause?
Federal Conservative party leader Pierre Poilievre speaking at one of his "Common Sense" rallies in July 2023.

The question is not whether the Senate can exert its constitutional powers, but when and how. And motion tabled by Sen. Peter Harder suggests at least one answer to the question of when.