The late chief justice Earl Warren once said that democracy was safe as long as Americans cared about vital issues. This is only right as far as it goes, for caring too much about issues is actually a threat to democracy.
Let's say a group of Americans feel that all left-handed people whose first names begin with J should not get drivers' licenses, and that they care so much that they are unwilling to accept a popular majority outcome on this issue. They will not wait for two or four years to try again, and they think violence is the only answer.
Caring too little can harm democracy; so can caring too much. As T.S. Eliot once wrote, "teach me to care and not to care; teach me to sit still."
He was talking about life. But he could have been talking about democracy.