To answer your question, if you have a democratic government that believes in free speech, rule of law, citizens rights etc then you would not allow someone who is opposed to these to have power or influence in the state.
Think the USA and its anti-communist stand in the 50's and 60's; McCarthy and all that went on then, the "evil empire" of Reagan.
The Quran speaks about those who are opposed to the right way of life that the Quran asks us to bring about and these are the ones that should not be allowed to have positions of power or influence in the state.
A good Jew, Christian or anyone else that lives under Islamic rule is allowed to practice their religion, build synagogues and churches, including in Saudi Arabia as these were present at the time of the Messenger and he protected them, and though they do not have the values that are present in the Quran [majority muslim in same boat!] that DOES NOT MAKE THEM VALUELESS. They are still human beings worthy of dignity and respect.