The Declaration of Independence doesn't actually say that. It says that everyone is endowed with certain unalienable rights including the right to life, liberty, and the pursuit of happiness.

Everyone has the right to life, liberty, and the pursuit of happiness whether they deserve it or not. Just like people have the right to free speech or a jury trial in front of their peers, whether they deserve it or not.

The distinction is important because whether someone deserves something is a normative statement while having the right is a descriptive statement.

What you deserve because of your right to life, liberty, and the pursuit of happiness is up for debate.