People can and do disagree on this topic.
Many people see these two things as necessarily opposed to one another. They feel that any increase in civil liberties will lead to a decrease in homeland security, and vice versa. The idea here is that the only way to increase security is to allow the government to have more of an ability to intrude into people’s lives. We can only increase homeland security by, for example, giving the government more of an ability to conduct surveillance on people within the United States. In this view, security and liberty are part of a zero-sum game.
However, there are others who argue that this is an incorrect view. They say that there are ways to make it so that the government can provide us with more security without taking away any of our liberties. In this view, what the government needs to do is to find more creative (and, they would say, more effective) ways of providing security. Instead of simply taking away civil liberties, they say, the government can respect liberties while finding other ways to protect us from terrorists.
My own view is that this is not necessarily a zero-sum game, but that it often will be because it is hard to determine what sorts of government actions can provide us with more security without also taking away some of our liberties.