Aaron Eckhart and Radha Mitchell appeared in the previous movies as the president and Leah. Why didn't they reprise their roles?
Probably because the first one was terrible, I looked it up and couldn't believe that this is the third film in the series. How on Earth was there a sequel, I'll never know.
I LIKED BOTH FILMS.THE FIRST BEING THE BEST.
I enjoyed both films as well. They broke out of the usual Hollywood paradigm of the Vast Right-Wing Conspiracy.
As Aaron Eckhart always says "You either leave a franchise or you stay long enough to see the hero become the villain".