How many cycles have they been promising to close Guantanamo now? It's never going to happen, they know it and we know it. Neither American party Establishment cares about liberty in a principled way.
Rights of the accused and prisoner rights are still a matter of liberty, even for the most repugnant of monsters.
It's not about wanting terrorists to have an easier time, it's about not letting The State have an inch on setting a precedent of unaccountable power & lack of transparency.
If you let The State con you into believing that their civil liberties violations will start and end with evil terrorists who "deserve it" -- Boy, do I have a Flat Earth tour to sell you.
The 'unpleasant' to look at, easy to dismiss violations of civil liberties (like those that have occurred at Gitmo) are both the first to be permitted by both sides of the Establishment, and also the violations people should care about most.
Just like with anti-free speech laws (and people who support them) -- State oppression wins when society permits the conflation of defending rights, with defending the person whose rights are being violated. Two very different things.