While Jack and his allies always seem to end up accomplishing their goals -- save the president/country/world -- they do so through very iffy means, including torture, deception, and much more. All of this sends a strong message that the "right" ends can justify the means, no matter what those means might be. The show also clearly takes the perspective that it's worth sacrificing almost anything for the greater good and places a strong emphasis on duty and loyalty.
Intense violence -- torture, gunplay, stabbing, poisoning, explosions, plane/car crashes -- sometimes with blood.
Fairly infrequent sexual references/activity, though characters (mostly women) do end up scantily clad in some scenes, and sex (whether for pleasure or as an act of manipulation) is sometimes implied via bedroom scenes.
Very frequent use of "dammit" by Jack; other words include "hell" and "bitch."
FOX News plays a major role in the show. The Sprint logo is visible on constantly-in-use cell phones, and many vehicles are product placements as well.
Drinking, Drugs & Smoking
Jack used to use heroin but talks about it with regret. Minor characters drink and smoke.