Tarkin is first a Captain and last a Grand Moff but always an extremist

Captain Tarkin is on the right

For those of you who are fans of the original Star Wars movies, you may remember Grand Moff Tarkin having this little exchange with Princess Leia:

"The more you tigthen your grip, Tarkin, the more star systems will slip through your fingers."
                                       --Leia Organa to Grand Moff Tarkin

We get to know Tarkin a lot better in the cartoon series The Clone Wars. One of the episodes I'm thinking of is "Citadel" and it's subsequent sequels that take place near the tail end of the third season. In that episode, Captain Tarkin and Jedi General Even Piell undertook a mission to find the Nexus Route, a strategically valuable hyperspace route which would lead into both the heart of the Galactic Republic and the Confederacy of Independent Systems (that's where all the Separatist planets are). During the mission, they were ambushed and attacked by Separatist forces. Before they got boarded, Piell and Tarkin each memorized half of the information regarding the Nexus Route before erasing it from the ship's computer files. After being forced to surrender, Tarkin and Piell, along with other officers were taken as prisoners to the Citadel, a Separatist prison on Lola Sayu.

Captain Tarkin at the end of season five sentencing Ahsoka Tano for
bombing the Jedi Temple. His manner, appearance, and uniform strike
me as being very "Nazi" ish, which I'm sure is intended.

Needless to say, Obi-Wan Kenobi, Anakin Skywalker, and padawan Ahsoka Tano rescue Tarkin from the Citadel. However, not before Tarkin let's loose with this little bit of conversation to Anakin:

Anakin:  "You lack faith in the Jedi."
Tarkin:  "I find their tactics ineffective. The Jedi Code prevents them from going far enough to achieve victory, to do whatever it takes to win, the very reason why peacekeepers should not be leading a war."

Basically, what Tarkin says reminds me of what I think a dictator would say. You know...the kind like Assad of Syria that would feel it's okay to turn chemical weapons on his own people. Also, with regard to the above quote, Anakin agrees with Tarkin in that episode. All the signs were there. Obi-Wan should not have been surprised that Anakin went to the Dark Side so easily. In this YouTube clip Anakin and Tarkin exchange words, basically trying to outdo each other on how well they know Chancellor Palpatine (he later becomes the Emperor).

I'm pretty sure that at the time of Star Wars: A New Hope arrived, Tarkin was the most powerful non-Force user in the Empire. I think he even outranked Vader, but don't quote me on that. It just sure seemed like it.