The only way to prevent activist judges is to hold them accountable. Who would they be accountable to? The people. The constitution was written for the U.S. and hence the people.
Judges can be held accuntable directly by the people voting for or against them. Appointments by the president and governors and approval by the elected officials is not working.
Let the people decide who should be judging them.
"What is the proper remedy?"
Perhaps it is time for "We the People" to reenact the Declaration of Independence.