When sufferings become insufferable…

The Declaration of Independence states that, “…all experience hath shown that mankind are more disposed to suffer while evils are sufferable than to right themselves by abolishing the forms [of government] to which they are accustomed…”  This phrase has intrigued me for many years.  I always wondered just where that point is reached within the frame work of a free People when they say, “The sufferings are no longer sufferable.”