What you need to be thinking about here is what role white opposition played in the Civil Rights Movement. This can help you answer both parts of the question.
First, the courts only drove civil rights advances through 1954. The Brown decision was the last major court decision that is remembered as helping the movement. So, you need to think about why courts were important in the early part of the movement. I would suggest that it was because there would have been too much white opposition to the movement at that point and so the courts were the only way to go. At that early stage, then, the movement was hindered by white opposition.
But then, as the movement really got going with the Montgomery Bus Boycott and the sit-ins of 1960, things changed. White opposition became very helpful to the movement. Imagine how different things would have been if people had not abused the Little Rock Nine or the people doing the sit-ins in Greensboro. Imagine if Bull Connor had not had the Birmingham police attack marchers with dogs and fire hoses. The movement would not have gotten anywhere near the sympathy it got and it would not have succeeded as well as it did.