"I would remind you that extremism in the defense of liberty is no vice! And let me remind you also that moderation in the pursuit of justice is no virtue." -- former AZ Senator and ultra conservative Barry Goldwater, in accepting the 1964 nomination from the Republican Party for President.
Of course, it depends on what you interpret as defending liberty. Unlike his orthodox conservative Republican predecessors, Goldwater, born 120 years ago today, represented more of the "libertarian" brand in his party and paved the way for such ultra conservatives as Ronald Reagan. His ideology infuses much of what we now see in the Republican / New Confederate / Active Shooter party: fetishizing gun "rights" over public safety, rejection of any government "solutions" to economic / social problems, deregulation that serves corporate interests, promoting selfishness over common purpose, etc. Although it's likely he would have been disgusted by Trump personally, Goldwater's subjective "extremism" as expressed in his speech helped spark the movement that eventually put Trump in power, and threatens democracy today.